To see the other types of publications on this topic, follow the link: Influenza vaccines.
Dissertations / Theses on the topic 'Influenza vaccines'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Influenza vaccines.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Parker, Christopher S. "Effect of a codon optimized DNA prime on induction of anti-influenza protective antibodies." Worcester, Mass. : Worcester Polytechnic Institute, 2007. http://www.wpi.edu/Pubs/ETD/Available/etd-040907-100839/.
Full text
2
Hartgroves, Lorian Cedar Safir. "Strategies for influenza vaccines." Thesis, Imperial College London, 2009. http://hdl.handle.net/10044/1/5558.
Full textAbstract:
The high mutation rate of influenza virus results in antigenic drift, meaning that each of the three components in the trivalent influenza vaccine are updated regularly so that the vaccine antigen closely matches the predominant or emerging strain. The production of influenza vaccines from the chosen seed has relied on embryonated chickens eggs for more than 40 years. Recent technological advances have resulted in the evaluation of several cell lines as alternative substrates for influenza vaccine production. Reverse genetics of influenza viruses allows the creation of viruses at will from cDNA. However, licensed cell lines have so far proved unpermissive for virus rescue and permissive lines remain largely unlicensed. A reverse genetics system for the production of influenza vaccines in PER.C6 cells has been developed and optimised. Many recent clinical isolates do not grow in eggs and hence require reassortment with a high growth, egg permissive backbone. Adventitious agents aside, cell lines able to support growth of clinical isolates could be used directly included in the vaccine, without the need for reassortment. However, this could lead to year on year variation in the quality and characteristics of the vaccine. Particularly pertinent, is the variation in the amount of IFN a clinical isolate can induce, which could severely limit yields. Yields and effects of IFN for a panel of high and low inducing viruses are investigated in a number of potential vaccine cell lines. The mechanisms behind virus IFN induction have been investigated. Using a panel of high and low inducing viruses the differences in growth and viral protein expressions, and activation of PRR has been analysed. The IFN response in PER.C6 cells has been characterised. Through an improved understanding of the mechanisms of IFN induction and inhibition, antagonists could be introduced into the vaccine cell line to improve yields.
3
Ni, Lihong. "Modeling vaccination for pandemic influenza implication of the race between pandemic dynamics and vaccine production /." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/hkuto/record/B40687430.
Full text
4
Wang, Yi Jennifer. "The optimal allocation of investment between antivirals and vaccines for influenza pandemic preparedness planning." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B41712018.
Full text
5
Porter, Suzette. "Tracking influenza immunization in the community /." Internet access available to MUN users only, 2003. http://collections.mun.ca/u?/theses,163880.
Full text
6
Khan, Tila. "Tailored influenza virus vaccines for both the young and old: Vaccine Efficacy of Whole Inactivated Vaccines bearing Immunomodulatory Adjuvants or Multimeric peptides." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/77130.
Full textAbstract:
Influenza epidemics and pandemics remain a significant burden to world health and economy. Low efficacy of current inactivated influenza vaccines in the elderly and immunocompromized and the inability to protect against antigenically drifted or shifted strains of influenza virus are the two major problems in influenza vaccine research. To overcome these hurdles, we have utilized an in vitro cell culture vaccine platform, which results in whole inactivated influenza vaccine (WIV) bearing bioactive membrane-anchored immunomodulatory proteins such as cytokines on the virion surface, collectively known as CYT-IVACs (Cytokine bearing-Inactivated Vaccine). In addition, we tested whether a multimeric M2e peptide presented on WIV can serve to enhance immunogenicity and augment protective efficacy of whole virus vaccines. Our panel of cytokines includes IL-2, IL-4, IL-12, IL-23, and Flt3L as well as the multimeric M2e peptide, all fused to the membrane anchoring regions of influenza virus hemagglutinin protein and constitutively expressed in virus permissive MDCK cell line. Subsequent infection with influenza virus results in incorporation of fusion constructs directly into budding progeny virions that are harvested, purified and inactivated to generate distinct CYT-IVAC formulations. Following validation of immunomodulator incorporation, vaccines were tested for in vivo efficacy in either "young adult" or "aged" female Balb/c mice. Our results demonstrate that our CYT-IVAC~IL-12/HA and CYT-IVAC~IL-23/HA serve as potent mucosal adjuvants in young adult mice elicited significantly high levels of mucosal IgA antibodies and afford superior protection against lethal virus challenge. Our Flt3L/HA formulation was the most effective stimulator of systemic anti-viral antibody levels. In "aged" mice a single dose formulation of IL-12 bearing CYTIVAC was superior at affording protection against lethal homotypic virus challenge. Finally, administration of multimeric M2e molecule co-presented on WIV elicited prolonged antibody responses in "young adult mice" and provided cross-protection from challenge with the heterologous influenza A pandemic strain 2009 H1N1. In conclusion, the CYT-IVAC approach represents a novel tailored advancement to current WIV approaches that has the potential to elicit both potent mucosal and systemic immune responses in young and old.Ph. D.
7
Yang, Zheng, and 楊爭. "Identification of non-HIV-derived (poly)peptides as primary immunogens for HIV-1 vaccine development and localization of two dominant ADCC epitopes on hemagglutinin antigen of pandemic H1N1 influenza virus." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/208007.
Full textAbstract:
Development of effective vaccines against mutable viruses (i.e HIV-1 and influenza) remains a big challenge. Antibody-dependent cell-mediated cytotoxicity (ADCC) has been found to be a key component of immune protection against viral infections in vivo. Therefore, vaccine immunogens that elicit broadly neutralizing antibodies with high ADCC are desired for vaccine development. This study is to identify primary immunogens that can initiate somatic maturation of germline antibodies of known broadly neutralizing HIV-1 antibodies (bnAbs) for HIV vaccine development and to localize dominant ADCC epitopes on hemagglutinin (HA) of pandemic H1N1 influenza virus for development of a flu vaccine.
Based on the observations that known HIV-1 bnAbs have extensive somatic mutation compared to their germline versions and that HIV-1 envelope (Env) glycoprotein lacks measurable binding to putative germline antibodies of known bnAbs, we hypothesized that non-HIV-derived (poly)peptides may serve as primary immunogens to trigger somatic maturation of germline antibodies of bnAbs, leading to elicitation of intermediate antibodies (iAbs) that can further mature to HIV-1 bnAbs upon Env vaccination or HIV-1 infection. Using b12 as a model bnAb, we identified five non-HIV-derived (poly)peptides that bound to putative b12 germline and iAbs, and immunized rabbits with the (poly)peptide priming followed by Env boosting. Rabbit immunization with (poly)peptides alone induced high titers of antibodies that were cross-reactive with gp140SF162 trimer and resurfaced Env RSC3, and the serum IgGs neutralized SF162 and JRFL. These results suggest that the (poly)peptides might structurally mimic CD4bs of Env. Priming rabbits with (poly)peptides followed by boosts with gp140SF162 and RSC3 resulted in antibodies capable of competing with b12 for binding to gp140SF162 trimer and neutralizing cross-clade isolates, while control rabbits without priming produced antibodies that were unable to compete with b12 for gp140SF162 trimer binding, and the serum IgGs neutralized only 3 clade B isolates. Our results provide proof of concept that non-HIV-derived (poly)peptides may serve as primary vaccine immunogens to initiate guided immune responses towards bnAbs.
HA protein has high level of immunogenicity and considered the most important target for immune protection against influenza virus infection. Several potent HA-specific bnAbs have been reported with their conserved neutralizing epitopes revealed, but there has been no report so far about ADCC epitopes on HA. Using yeast display and flow cytometry assisted cell sorting, we mapped the epitope of convalescent plasma IgGs with different ADCC activity, we identified two dominant ADCC epitopes, designated HA-E1 [AA92-117] and HA-E2 (AA 124-159), on HA of 2009 pandemic H1N1 influenza virus. E1 and E2 overlapped with the immunodominant epitopes of HA. Depletion of purified patient plasma IgGs with yeast cells expressing E1 or E2 peptides decreased ADCC activity of the IgGs. E1 and E2 sequences are highly conserved in H1N1 strains, but less so in other subtypes of influenza A viruses. Our study may aid in designing immunogens that can elicit antibodies with high ADCC activity. Vaccine immunogens designed to include the structural determinants of potent bnAbs and ADCC epitopes may confer a comprehensive immune protection against influenza virus infection.published_or_final_version
Microbiology
Doctoral
Doctor of Philosophy
8
Preis, Julia Kay. "Market incentives for pandemic influenza vaccines." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/78155.
Full textAbstract:
Thesis (S.M. in Health Sciences and Technology)--Harvard-MIT Program in Health Sciences and Technology, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 60-61).
It has been estimated that 100 million plus individuals could perish if a virulent influenza pandemic were to occur. In wake of the 2009-10 H1N1 pandemic and in an era of economic austerity, however, industry lacks clear incentives to invest in vaccines for other high-risk strains. The cyclic nature of pandemics also means we can expect another influenza pandemic within the next 20 years. In this environment, design of incentive mechanisms for funding development of vaccines against strains with known pandemic potential, but for whom vaccine technology is currently lacking, would be welcomed. This research explores which novel incentive mechanisms could induce investment in and development of processes for production of vaccines for these high risk strains. Interviews with vaccine developers and funding agencies and analysis of the pipeline of influenza vaccines in development were conducted. This thesis finds that there is a dearth of vaccines against influenza strains of known pandemic potential, such as H2, H7 and H9; that current pandemic preparedness efforts are not focused on these strains; that funding for pandemic preparedness efforts in H2, H7 and H9 would help incentivize development of vaccines against these strains; and that support for seasonal influenza, regulatory changes, alignment of public and private sector goals, and increased vaccine acceptance are also required to incentivize the development of vaccines against strains of known pandemic potential such as H2, H7 and H9. Furthermore, this thesis recommends that policy makers increase funding for pandemic preparedness so that programs may be initiated or expanded to include additional high risk influenza strains; that US and EU regulatory regimes for pandemic influenza vaccines be harmonized; and that governments promote public awareness of the importance of influenza vaccination.
by Julia Kay Preis.
S.M.in Health Sciences and Technology
9
Fitzner, Karen A. "An economic assessment of influenza prevention in Hong Kong." Thesis, Hong Kong : University of Hong Kong, 1996. http://sunzi.lib.hku.hk/hkuto/record.jsp?B19670254.
Full text
10
王軼 and Yi Jennifer Wang. "The optimal allocation of investment between antivirals and vaccines for influenza pandemic preparedness planning." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B41712018.
Full text
11
Li, Zhiyuan, and 李致媛. "Impacts on influenza A(H1N1)pdm09 infection from seasonal influenza vaccine and related regional factors : systematic review and meta-analyses." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/193796.
Full textAbstract:
BACKGROUND
Influenza is an infectious disease that has significant public health impact due to its high prevalence and mortality. In early 2009, a novel influenza A(H1N1) virus emerged in Mexico and the USA, then rapidly spread worldwide and caused the first influenza pandemic of the 21st century. However, it is still controversial that whether seasonal influenza vaccine can provide a cross-protection against influenza A(H1N1) pdm09 infection. Since the 2009 pandemic occurred, numbers of studies focusing on this issue have been published, yet no confirmed conclusion was drawn. Therefore, further quantitative evaluation is needed to provide more reliable evidence. The objective of this study is to assess the cross-protection of seasonal influenza vaccination against 2009 pandemic A(H1N1) influenza illness, and explore the impact of seasonal influenza activities on this association.
METHODS
I followed the PRISMA statement and searched the PubMed, MEDLINE, Ovid Embase, The Cochrane Library databases, SCOPUS and CNKI. Randomized control trials, cohort studies, case-control studies assess the effect of seasonal influenza vaccine against influenza A (H1N1)pdm09 illness published in English and Chinese from 2009 to July 2013 were identified. The quality of included studies was assessed by the Jadad scale and the Newcastle-Ottawa Scale. I used the I2statistic, and Begg's funnel plot for assessment of heterogeneity and publication bias respectively. The software Review Manager 5.2 was used for generating the pooled effect with corresponding 95% confidence intervals and forest plots. Subgroup analysis was performed based on the study locations and previous circulating influenza viruses.
RESULTS
20 studies were included in the meta-analyses. There is a non-significant 19% reduced risk of pandemic influenza illness in the countries combined data based on case-control studies(OR=0.81, 95% CI=0.60 to 1.08). While, for RCTs, a non-significant increase risk in seasonal influenza vaccinees was observed(RR=1.13, 95% CI=0.56 to 2.29). For the subgroup analysis, a significant 35% to 50% cross-protection was observed in South America and Europe, but an opposite result was observed in Canada(OR=1.44, 95% CI=0.83 to 2.50). Besides, the results indicate that there is no association between seasonal influenza vaccination and ILI. No publication bias was detected.
CONCLUSIONS
The findings partially support the hypothesis that seasonal vaccine may offer moderate cross-protection against laboratory-confirmed pandemic influenza A(H1N1) illness in general. Further immunological research is needed to understand the mechanism behind these findings.published_or_final_version
Public Health
Master
Master of Public Health
12
Lee, Sze-tsai Esther, and 李思齊. "A review of seasonal and pandemic influenza vaccine recommendations bydifferent countries." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45172845.
Full text
13
Pang, Wing-yan, and 彭詠欣. "Systematic review of factors influencing seasonal influenza vaccine uptake among health care workers." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/206955.
Full textAbstract:
Introduction: Influenza is one of the commonest infectious diseases among human beings. The annual attack rates were 5-10% and 20-30% in adult and children respectively around the world. Fortunately, this is a vaccine preventable disease. Vaccinating health care workers can reduce risk of infection among themselves so as to maintain the availability of health care services. This can also prevent nosocomial infections and associated morbidity and mortality of their patients. The World Health Organization recommended 60% influenza vaccination coverage by 2006 in high risk groups and targeted 75% by 2010. However, the vaccine uptake rate among health care workers is still low globally. The vaccination coverage is in Western Europe 20-40%, in Hong Kong 30%, in Australia 16-60% and in the United States 63.5%. This systematic review aims at identifying the factors influencing influenza vaccine uptake among health care workers which can help formulation of future vaccination strategies so as to protect health care workers themselves and their patients.
Methods: Electronic databases (PubMed, MEDLINE and eKG) of journal articles published after January 2011 using title and keywords related to health care workers and influenza vaccination uptake were searched. Predefined inclusion and exclusion criteria were applied. Data were extracted and quality was assessed from the eligible studies using individualized data extraction form and quality assessment form by two reviewers. The reasons of vaccination acceptance and declination were divided into different categories. A score was given to each category according to the percentage of respondents stating that as an important influencing factor. The factor with higher score indicated the more important it is. The predictive factors positively associated with vaccination acceptance were retrieved from results of multivariate logistic regression models of the studies which had an odd ratio greater than one. The PRISMA statement is used to guide the methodology and reporting of the studies.
Results: Nine eligible studies were finally identified. The studies reviewed found that the reasons behind low seasonal influenza vaccination uptake rate among health care workers are complex and made up by both perceptual and organizational factors. For factors of influenza vaccination acceptance, self protection, risk perception, and protection of patients were identified as the most important. For factors of influenza declination, concern of vaccine side effects, lack of concern, and doubts of vaccine safety and efficacy showed the greatest influence. Convenient vaccination location and time was suggested to be the strongest predictive factor which positively associated with future vaccination uptake.
Conclusion: As influenza vaccination is an effective measure to prevent infection among health care workers and nosocomial infection of their patients, annual seasonal influenza vaccination program is essential in health care settings. In order to promote annual seasonal influenza vaccination among health care worker, multipronged approach is recommended. Targeted educational intervention can be used to overcome the perceptual barriers on misconception about influenza and influenza vaccines. The organizational barriers can be fixed by introducing mobile vaccination team which provide services in flexible period of time around the workplace.published_or_final_version
Public Health
Master
Master of Public Health
14
Li, Kwok-fai Michelle. "A mathematical model on optimizing the dose of pre-pandemic influenza vaccines." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B4299505X.
Full text
15
Lin, Shilin Cindy. "Effect of multiple annual vaccinations against influenza in the young and the elderly a literature review /." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B4299732X.
Full text
16
Yuen, Yuet-sheung Carol. "Educational and promotional guidelines to improve influenza vaccine coverage of health care workers." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B43251845.
Full text
17
Brown, Melissa. "Assessing Knowledge and Behavior Regarding Influenza Vaccines." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1281715985.
Full text
18
Dannetun, Eva. "Reasons for non-vaccination /." Stockholm, 2006. http://diss.kib.ki.se/2006/91-7140-739-1/.
Full text
19
Macías, Hernández Alejandro E., Fortino Solórzano Santos, Velasco Hugo M. Aguilar, Agüero María L. Ávila, Fernando Bazzino Rubio, Bellei Nancy C. Junqueira, Pablo E. Bonvehí, et al. "Influenza tetravalent vaccines in national immunization programs for Latin-American countries." Comunicaciones Cientificas Mexicanas S.A. de C.V, 2020. http://hdl.handle.net/10757/655697.
Full textAbstract:
Since 2012-2013 influenza season, World Health Organization (who) recommends the formulation of tetravalent vaccines. Globally, many countries already use tetravalent vaccines in their national immunization programs, while in Latin America only a small number. Two Influenza b lineages co-circulate, their epidemiological behavior is unpredictable. On average they represent 22.6% of influenza cases and more than 50% in predominant seasons. The lack of concordance between recommended and circulating strains was 25 and 32% in the 2010-2017 and 2000-2013 seasons, respectively. There are no clinical differences between influenza A and B. It occurs more frequently from five to 19 years of age. Influenza b has a higher proportion of attributable deaths than influenza a (1.1 vs. 0.4%), or 2.65 (95% ci 1.18-5.94). A greater number of hospitalizations when the strains mismatch (46.3 vs. 28.5%; p <.0001). Different evaluations have demonstrated its cost effectiveness. The compilation of this information supports the use of quadrivalent vaccines in Latin American countries.Revisión por pares
20
Davydova, T. V. "Characteristic of immunogencity of seasonal influenza vaccines." Thesis, Сумський державний університет, 2013. http://essuir.sumdu.edu.ua/handle/123456789/32145.
Full textAbstract:
Influenza at the present stage is a serious problem, it is the only disease that over the past decade has caused a pandemic. Immunisation is the most important way to contain the infection.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/32145
21
Singh, Gagandeep. "RNA Viral Prophylaxis: Problems and Potential Solutions." Diss., North Dakota State University, 2019. https://hdl.handle.net/10365/29458.
Full textAbstract:
Over 80% of the newly emerging infectious diseases are caused by RNA viruses. Major global problems associated with the development of vaccines against the RNA virus are their high genetic and antigenic diversity. Hence, effective control of epidemics with newly emerging RNA viruses require improved vaccines which are either specific to the new strain or broadly effective even when new viral strains emerge. The main focus of this dissertation is to develop epidemic vaccines using these two approaches. Using a newly emerged swine enteric virus called porcine epidemic diarrhea virus (PEDV) as a model, our first goal was to develop a quick and easy method for rapid response vaccines with potential applicability to a range of RNA viruses. We hypothesized that the methods which can disrupt genomic RNA without impacting the structural integrity of the virus would result in attenuated vaccine with minimum replication in the host while inducing immune responses. As hypothesized, developed rapid response PEDV vaccine induced complete protection against the virulent challenge virus, while vaccine viral shedding was not detected in vaccinated pigs. To address the second problem of rapid viral evolution leading to vaccines becoming obsolete, we used swine influenza virus (SIV) as a model to develop and test a universal vaccine composed of peptides encoding conserved antigenic epitopes which are present in most influenza A viruses. Importantly, a novel amphiphilic invertible polymer (AIP) was used to address the well-recognized problem of poor antigenicity of peptides. We hypothesized that peptides encoding conserved epitopes when conjugated with an AIP will induce strong immune responses and protect against challenge virus. While the conserved epitopes were previously tested by others in mice, we were the first to test a combination of these epitopes in pigs. Pigs vaccinated with the peptide polymer vaccine mounted strong antibody responses against the epitopes indicating that the delivery system was effective. However, protection against replication of the challenge virus was delayed. In summary, the methods developed and tested in this body of work significantly contribute to the area of emergency response management in infectious disease outbreaks.United States Department of Agriculture, National Institute of Food and Agriculture (USDA-NIFA)
North Dakota State Agricultural Products Utilization Committee (ND APUC)
North Dakota State Board of Agricultural Research (ND SABRE)
22
Li, Tsz-wai, and 李梓維. "Efficacy of combined influenza and 23-valent pneumococcal polysaccharide vaccines in chronic smokers." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/202310.
Full textAbstract:
Background
Chronic smokers are at risk of premature death associated with underlying pulmonary or cardiovascular diseases. Dual influenza and pneumococcal vaccination has been shown to prevent death and hospitalization secondary to pulmonary or cardiovascular diseases in elderly persons. Its effect in chronic smokers remained unknown.
Methods
This is a prospective randomized open-labeled trial conducted from April 2010 to March 2013, comprising adult patients aged less than 50 years who were chronic smokers. Subjects were randomly assigned into 4 groups. Group 1 (study group) patients received both trivalent influenza vaccine (TIV) and the 23-valent polysaccharide pneumococcal vaccine (PPV). There were 3 control groups: Group 2 patients received the TIV only. Group 3 patients received the PPV only and Group 4 patients did not receive any vaccines. The TIV used was the Vaxigrip® (Sanofi Pasteur, France) and the PPV used was the Pneumovax®23 (Merck, USA). All enrolled patients were follow-up for 24 months post vaccination. Patient details, Charlson comorbidity index, medications, subsequent hospitalization, diagnosis and mortality were recorded and analyzed.
Results
A total of 1006 subjects were enrolled and completed the study (Group PPV+TIV: 250; Group TIV: 254, Group PPV: 250 and Group None: 259). The baseline demographics and Charlson comorbidity index were similar among subjects in the 4 groups. The median age was 48 years and 85.9% were male patients. Significantly fewer subjects who received the dual vaccination (Group PPV+TIV) were hospitalized (p<0.001), with shorter mean length of stay (p<0.001), and less frequent hospitalization (p<0.001) for cardiovascular or respiratory diseases than no vaccination (Group None) or single vaccination (Group TIV and Group PPV). Multivariate analysis demonstrated that dual vaccination with PPV + TIV was the only independent factor associated with reduced risk of hospitalization (p<0.001; relative risk 0.288; 95% CI 0.101-0.154). There was no difference in mortality rate among the groups. Both vaccinations were well tolerated and no serious adverse events were reported.
Conclusion
Dual influenza and pneumococcal vaccinations prevented chronic smokers against hospitalization secondary to pulmonary or cardiovascular causes. Annual influenza and a single pneumococcal vaccination should be promoted among chronic smokers.published_or_final_version
Microbiology
Master
Master of Medical Sciences
23
Chandler, Garvin Lee Kearney Christopher Michel. "Influenza hemagglutinin expression in Nicotiana tabacum and Nicotiana benthamiana." Waco, Tex. : Baylor University, 2007. http://hdl.handle.net/2104/5049.
Full text
24
Zhang, Naru, and 张娜茹. "Study on influenza virus-like particles and ssDNA aptamers." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/200167.
Full textAbstract:
Since there is an urgent need for development of vaccines and antiviral agents to combat influenza pandemics, this study aimed to develop influenza virus-like particles (VLPs) and aptamers targeting the virus particles as vaccine and antiviral agent candidates.
Influenza VLPs containing three structural proteins of hemagglutinin (HA), neuraminidase (NA) and matrix 1 (M1) derived from influenza A/Hong Kong/01/2009 (H1N1) virus (HK/01) were constructed using a Bac-to-Bac baculovirus expression system. The expressed VLPs were purified by sucrose density gradient ultracentrifugation and characterized by Western blotting analysis and transmission electron microscopy. The immune responses and protective efficacy induced by VLPs were compared with those elicited by the clinically used Panenza vaccine in BALB/c mouse model. The results showed that two-dose vaccination with both VLP and the Panenza vaccine could confer complete protection. Single-dose vaccination with VLP could also provide 100% protection against lethal virus challenge, whereas single dose of an equal amount (based on HA content) of the Panenza vaccination just provided incomplete protection (67% survival rate) against the lethal virus challenge. Compared to the Panenza vaccination, the VLP vaccination could induce higher and broader antibody responses and higher viral specific T help (Th) cell and cytotoxic T lymphocyte (CTL) responses. Notably, a novel finding in this study is that the VLP vaccination could induce antibodies to inhibit virus release from infected MDCK cells, although the underlined mechanism needed to be further studied. These results indicated that influenza VLP might be a more effective and safe vaccine candidate which could be developed into an alternative vaccine for the control of epidemic and pandemic influenza in the future.
To develop aptamers as antiviral agents against influenza, I sought to use influenza VLPs as target for ssDNA aptamer selection. After 11 rounds of selection using the systemic evolution of ligandsby exponential enrichment (SELEX),the recovered DNA molecules were PCR-amplified, gel purified and cloned into pCR-Blunt II TOPO vector for sequencing. The sequencing results showed that one aptamer Va-1 was markedly enriched, which was accounted for 59% (13/22) of the selected aptamers. Compared to the other non-enriched aptamers, the enriched aptamer Va-1 showed the highest binding affinity to the UV inactivated influenza HK/01 virus. It was also shown that the aptamer Va-1 specifically bound to the HK/01 stain while it could not bind other respiratory viruses even the PR8 strain within the H1N1 subtype. It was further demonstrated that the aptamer Va-1 could only bind to NA protein in a dose-dependent manner but not bind to HA and M1 proteins. Unfortunately, the selected aptamer did not show any antiviral effects. However, it may be potentially developed into a diagnostic and analytic agent because its binding activity was comparable with that of the commercial anti-NA antibody.
In conclusion, the influenza VLPs may be a promising vaccine candidate for the control of influenza virus infection and the selected aptamer may be potentially developed into an alternative tool for influenza virus detection.published_or_final_version
Microbiology
Doctoral
Doctor of Philosophy
25
Wang, Leyi. "STUDY TOWARD THE DEVELOPMENT OF ADVANCED INFLUENZA VACCINES." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1249332969.
Full text
26
Adedokun, Amos. "Perceptions of Healthcare Workers Toward Influenza Vaccination." ScholarWorks, 2018. https://scholarworks.waldenu.edu/dissertations/4992.
Full textAbstract:
Even though influenza vaccinations were provided free to all healthcare workers in the United States, healthcare workers were not 100% compliant. The non-compliance with influenza vaccinations may expose their patients, their families, and the public at large to a high-risk source of influenza infection. This study's research questions included how registered nurses perceived influenza and influenza vaccination; registered nurses' self-reported incidents with influenza vaccination; and factors that contributed to registered nurses' non-compliance with influenza vaccination. Guided by the theory of reasoned action and the theory of planned behavior, the purpose of this qualitative study was to determine the factors that contributed to the non-compliance of registered nurses with receiving the influenza vaccination. Twenty participants from a healthcare facility in Florida were interviewed using an interview guide. Audio data was transcribed to text data; text data was coded and thematically analyzed by using ATLAS.ti software. Results revealed that 70% of registered nurses were afraid of influenza vaccination, while 80% of them saw influenza vaccination as ineffective; 90% of them had bad experiences or have seen colleagues/friends who have had bad experiences after influenza vaccination. In addition, 40% of registered nurses claimed that they already had good immunity, while 20% of them declined influenza vaccination because of personal choices. Research findings from this study may be utilized to bring positive social change to society at large. The findings may be utilized to enhance existing strategies or policies or even help formulate new policies and strategies that would address the concerns of HCWs, especially registered nurses.
27
Ng, Sophia, and 吳鈺陪. "The role of antivirals and vaccines in the control of influenza epidemics and pandemics." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B49617849.
Full textAbstract:
Influenza vaccination is the best preventive measure against influenza virus infection, and antivirals including oseltamivir are effective treatments. From a public health point of view, it is important to evaluate whether vaccination and antiviral treatment reduces transmission of the virus. I analyzed data from a community-based study of influenza virus transmission in households, and identified effectiveness of antiviral treatment in reducing duration of illness and some evidence that treatment reduced transmission to household contacts. I also analyzed data from a community-based placebo-controlled trial of influenza vaccination and confirmed efficacy of vaccination against seasonal influenza but differential efficacy against pandemic influenza possibly because of timing and mediation of seasonal influenza epidemics. In further analyses I found that antibody titers of 1:40 correlated with 50% protection against infection, and repeated vaccination with the same strains tended to be associated with reduced responses to those strains although there was no evidence of reduced efficacy. In the study, one child in each household was randomly allocated to receive vaccine or placebo and I did not identify any evidence of indirect benefits to the household members of vaccinated children. I reviewed vaccine target groups in different countries, and noted that some countries now include school-age children in their target groups based mainly on the principle of herd immunity. My findings did not support the inclusion of school-age children as a target group for vaccination in Hong Kong. Further studies should examine the indirect as well as direct benefits of vaccination in different settings in order to guide optimal influenza vaccination policies.published_or_final_version
Community Medicine
Doctoral
Doctor of Philosophy
28
Kwan, Hoi-yee. "An international survey on the use of influenza vaccine and attitudes of clinical researches about a possible outbreak of influenza." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B40687442.
Full text
29
Wu, Wai-lan. "Antigenic characterisation of avian influenza H5N1 viruses in Asia : implications for vaccine strain selection /." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B41508270.
Full text
30
Ni, Lihong, and 倪莉紅. "Modeling vaccination for pandemic influenza: implication of the race between pandemic dynamics and vaccineproduction." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B40687430.
Full text
31
Lau, Lam. "Factors affecting influenza vaccination among non-instutionalized elderly persons in Hong Kong /." View the Table of Contents & Abstract, 2005. http://sunzi.lib.hku.hk/hkuto/record/B3149514X.
Full text
32
Lau, Tin-wai. "Effectiveness of influenza vaccine among elderly people living in residential care homes during outbreak situations." Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/b39724177.
Full text
33
Li, Kwok-fai Michelle, and 李國暉. "A mathematical model on optimizing the dose of pre-pandemic influenza vaccines." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B4299505X.
Full text
34
Wong, Laura Elizabeth. "Effects of influenza vaccination and temperature screening of day carechildren: a mathematical model." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B42997951.
Full text
35
Wong, Laura Elizabeth. "Effects of influenza vaccination and temperature screening of day care children a mathematical model /." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B42997951.
Full text
36
Gelder, Colin Malcolm. "Human CD4+ T cell recognition of influenza A haemagglutinin." Thesis, Imperial College London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339198.
Full text
37
Leung, Ho-chuen, and 梁浩銓. "A study of H5N1-M2e-based universal influenza vaccine." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/208568.
Full textAbstract:
The ectodomain of influenza matrix protein 2 (M2e) may be an ideal candidate in the development of influenza universal vaccine due to its highly conserved property among different subtypes/strains of influenza virus. M2e based vaccines have been extensively studied and potent cross-subtype/strain protections have been reported. However, more and more M2e mutants of influenza virus have been identified in recent years. It is still unclear whether M2e based vaccines are effective against these M2e mutants of influenza virus.
This study first evaluated cross-protection of an M2e tetrameric peptide vaccine based on H5N1 virus strain A/Vietnam/1194/04 (VN/1194-M2e) against lethal challenges of M2e mutants of H5N1 virus strain A/Hong Kong/156/97 (HK/156) and a novel H7N9 virus, because there are 3 or 5 amino acid differences between VN/1194-M2e and HK/156-M2e or VN/1194-M2e and H7N9-M2e. The results showed that the vaccination of VN/1194-M2e did not induce high level of cross-reactive antibodies against HK/156-M2e and just provided poor cross-protection against lethal challenge of HK/156 virus. In contrast, VN/1194-M2e vaccination induced high level of cross-reactive antibodies against H7N9-M2e. Consistently, the vaccination provided good cross-protection against lethal challenge of H7N9 virus. These results strongly suggested that some mutations in M2e, such as mutations at positions 10, 14 and 16 which found in HK/156 M2e, might affect the M2e vaccine efficacy, but some others, such as five mutations found in H7N9-M2e, might not be critical for the M2e immunogenicity.
This study then investigated the relationship between the M2e immunogenicity and amino acid mutations of the M2e. Beside VN/1194-M2e (P0), we synthesized additional 10 M2e mutant peptides which contain different single or multiple mutations. The 3D structures of these M2e peptides were predicted and analyzed. The prediction results showed that group 1 peptides (P0, P10, P14, P16, P18, P20 and P18-20) exhibited either irregular structures or loose hairpin structures which might associate with well exposure of antigenic epitope, whereas group 2 peptides (P10-14, P10-16, P14-16 and P10-14-16) formed tight hairpin structures in which antigenic epitope might bury inside their own secondary structure. Vaccination efficacies of these M2e peptides were evaluated in mice for antibody responses and cross-protection against lethal challenge of VN/1194 and HK/156 viruses. Our results showed that vaccinations of group 1 peptides induced high levels of cross-reactive antibodies against VN/1194-M2e and good cross-protection against lethal challenge of VN/1194 virus. However, vaccinations of group 2 peptides vaccinations induced significantly lower VN/1194-M2e antibody responses and poor cross-protection against lethal challenge of VN/119 virus. Furthermore, both group 1 and group 2 peptides could just induce low levels of cross-reactive antibodies against HK/156-M2e and poor protection against lethal challenge of HK/156 virus.
Although H5N1-M2e tetrameric peptide has been previously shown to protect mice from lethal challenges by different subtypes/strains of influenza virus, this study has shown that certain amino acid variations in M2e could weaken M2e immunogenicity but some others might not. The different secondary structures of M2es may probably associate with their immunogenicity. Our findings have provided valuable information for the development of M2e based universal vaccines.published_or_final_version
Microbiology
Doctoral
Doctor of Philosophy
38
Domnich, Alexander, Ilaria Manini, and Emanuele Montomoli. "CORRELATES OF PROTECTION AND HOST-RELATED MODIFIERS OF THE IMMUNOGENICITY OF INFLUENZA VACCINES: EVIDENCE MAPS AND EVIDENCE GAPS." Doctoral thesis, Università di Siena, 2021. http://hdl.handle.net/11365/1126528.
Full textAbstract:
Seasonal influenza is the leading infectious disease in terms of its health and socioeconomic impact. Annual immunization is the most efficient way to reduce this burden. To be clinically effective, influenza vaccines must be immunogenic, and several immunological assays to test their immunogenicity have been developed.
The overall aim of this PhD thesis is to provide the principal stakeholders (including scientists, healthcare professionals, policy-makers, pharmaceutical industry, etc.) with stateof-the-art knowledge and practices related to influenza vaccine-induced immunogenicity. To achieve this aim, we developed a novel empirical approach that incorporated some modern techniques, including, for example, evidence mapping. Basically, this thesis is composed of three main domains. In the introductory part, we will briefly cover the topics of influenza disease, influenza vaccination, the immunogenicity measurements of influenza vaccines and their correlates of protection. The second part, which is the core of the present project, is composed of two original case studies. The first study aimed to describe the patterns of use of the various immunological assays available to measure the influenza vaccine-induced adaptive immune response and to determine its correlates of protection. For this purpose, we analyzed 1,164 phase I–IV studies that enrolled a total of 754,935 subjects. Of the studies included in our analysis, 76.5% measured only the humoral immune response. Among these, the hemagglutination-inhibition assay was by far the most widely used. Other, less common,
humoral immune response assays were: virus neutralization (21.7%), enzyme-linked immunosorbent (10.1%), single radial hemolysis (4.6%) and assays able to quantify antineuraminidase antibodies (1.7%). By contrast, cell-mediated immunity was quantified in only 23.5% of studies. Several variables were significantly (P < .05) associated with the use of single assays. Specifically, some influenza vaccine types (e.g. adjuvanted, live attenuated and cell culture-derived or recombinant), study phase and study sponsorship pattern were usually found to be statistically significant predictors. In the second study, we went further by systematically analyzing host-related factors able to modify influenza vaccine-induced immunogenicity. To this end, a total of 28 systematic reviews/meta-analyses (with thousands of participants) were analyzed. These covered the following domains: intravenous drug use, psychological stress, acute and chronic physical exercise, genetic polymorphisms, use of pre-/pro-/symbiotics, previous Bacillus Calmette–Guérin vaccination, diabetes mellitus, vitamin D supplementation/deficiency, latent
cytomegalovirus infection and various forms of immunosuppression. In order to present effect sizes on the same scale, all meta-analyses were re-performed, whenever possible, and cumulative evidence synthesis ranking was carried out. Meta-analysis was conducted separately on each health condition category and virus (sub)type. A total of 295 meta-analyses were re-performed/performed ex novo; of these, 97 pooled estimates were used in order to construct an evidence-based stakeholder-friendly map. Finally, we discussed the principal findings, made some suggestions from the point of view of the various stakeholders and proposed a novel immunogenicity pathway.
39
Kim, Mi-so, and 金美昭. "Parental characteristics towards child vaccination against pandemic influenza H1N1-2009." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hub.hku.hk/bib/B50561686.
Full textAbstract:
Background
The pandemic of influenza A (H1N1-2009) virus was particularly widespread among children. Children and young adults were more likely to be infected than older adults, and infection among infants tended to lead to a higher risk of severe complications than among older children and adults. Vaccination against the virus was thus recommended as an effective countermeasure to protect these susceptible age strata from influenza infection and subsequent complications. Parental perception, attitudes and beliefs would thus play a major role in mitigating the pandemic influenza because these factors underlie the degree of vaccination uptake among children.
Objective
The primary aim of this study is to understand factors that are associated with parental acceptance of pediatric vaccination against influenza (H1N1-2009). The secondary aim is to consider the effective future vaccination campaign in the event of a pandemic and to increase child vaccination coverage.
Methods
We conducted a systematic literature search of the electronic databases, PubMed and the Web of Science. We identified and examined published literatures associated with parental acceptance dating back to the beginning of the 2009 pandemic. We extracted key datasets from these literatures, summarized the evidence systematically and determined the relationship amongst the aforementioned parental characteristics and acceptance of pandemic influenza vaccines.
Results
We included a total of 14 studies in this review. Our systematic review indicates that parents were more willing to accept H1N1 pandemic influenza vaccination if 1) their children had previous experience with seasonal influenza; 2) they have had the pandemic influenza vaccine themselves; or 3) they intended to have their children vaccinated against seasonal influenza vaccine. We also founded that parental perceptions and attitudes towards both the influenza pandemic itself and the pandemic influenza vaccine are significantly associated with acceptance. Our study identified misperceptions and distrust in vaccine safety as the main reason for parents to refuse pandemic influenza vaccination for their children. In addition, we found that parents usually received negative appraisal on pediatric influenza vaccination from the media and tended to regard health care workers as the most reliable source of information on pediatric influenza vaccination.
.
Conclusions
Parental perceptions are influential on pandemic influenza vaccine acceptance of their children. We affirm the importance of the role of health care workers in delivering appropriate information on influenza vaccines to parents in increasing pediatric vaccination uptake. We recommend public health officials to employ effective strategies for risk communication regarding pediatric influenza vaccines in order to increase the coverage and hence effectiveness of vaccination program against a future influenza pandemic.published_or_final_version
Public Health
Master
Master of Public Health
40
Kwan, Hoi-yee, and 關凱怡. "An international survey on the use of influenza vaccine and attitudes of clinical researches about a possible outbreak of influenza." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40687442.
Full text
41
Wu, Wai-lan, and 胡慧蘭. "Antigenic characterisation of avian influenza H5N1 viruses in Asia: implications for vaccine strainselection." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B41508270.
Full text
42
Macdonald, D. "Lentiviral vector vaccines for T-cell-mediated protection against influenza." Thesis, University College London (University of London), 2014. http://discovery.ucl.ac.uk/1417882/.
Full textAbstract:
Vaccines that induce T cells which recognize conserved viral proteins could confer cross-strain protection against pathogens with fast-mutating B cell epitopes. Influenza is an example of such a pathogen for which there is a pressing need for a universal vaccine. Lentiviral vectors are a counterintuitive choice as vaccines since they have low inherent immunogenicity. However, their efficient transduction of non-dividing cells and high capacity permits transduction of antigen presenting cells with not only antigen but also molecular adjuvants that directly or indirectly enhance the T cell response. We therefore investigated the potential of two such adjuvants: viral flice-like inhibitor protein, which activates dendritic cells through nuclear factor kappa-B, and 4-1BB ligand, which activates T cells directly through 4-1BB. By co-encoding these with influenza nucleoprotein, we have shown that the influenza-specific T cell response to lentiviral vector vaccination is significantly enhanced in mice. Furthermore, we have demonstrated that intranasally delivered lentiviral vectors transduce alveolar macrophages with high efficiency, recalling and expanding large and sustained populations of nucleoprotein-specific CD8+ T cells in the lung and airway in mice that have been primed subcutaneously or previously exposed to influenza. These lung-resident T cell populations persist for at least 4 months and are sufficiently abundant to rapidly control a mouse-adapted lethal influenza challenge without invocation of a secondary cytokine response, weight loss or lung injury. Furthermore, dendritic cells expressing 4-1BBL potently trans-activate bystander dendritic cells, both in vitro and in vivo, demonstrating an indirect mechanism by which the 4-1BBL:4-1BB signaling axis can enhance T cell responses.
43
Sofikiti, Antonia. "Application of emerging analytical technologies for characterisation of influenza vaccines." Thesis, University of Newcastle upon Tyne, 2017. http://hdl.handle.net/10443/3717.
Full textAbstract:
Novartis Vaccines (NV) in Liverpool operates an egg-based, semi-automated, influenza vaccine manufacturing facility with the capability to process a batch per day. This thesis focuses on the Agrippal base product, an inactivated subunit trivalent vaccine. The objectives of this multidisciplinary project included optimisation of assays and introduction of analytical technologies that could potentially facilitate characterisation of viral concentration, particle size and aggregation interactions with a view to promote understanding of product stability and identify opportunities for process optimisation and yield improvements in the Agrippal platform. The first phase of this project focused on methods of nanoparticle analysis that could enable efficient monitoring of viral content from the early stages of product development and throughout the downstream operations. A comparative evaluation between commonly used particle analysers showed that differential centrifugal sedimentation (DCS) is the most suitable method for the analysis of in-process influenza vaccine samples. Novel applications of DCS throughout the manufacturing of egg-based inactivated influenza vaccines were examined and are reported herein. DCS was proven to be a valuable analytical tool by demonstrating high potential for process investigation and monitoring. Key applications include direct determination of viral content in allantoic fluid, viral quantification at whole virus process stages, characterisation of unit operations on a particle based approach and detection and monitoring of the kinetics of aggregation. Furthermore, DCS was specifically employed in a novel study entailing direct determination of influenza virus growth in allantoic fluid upon addition of glucocorticoids and other compounds (hydrocortisone, dexamethasone, corticosterone, AFZ077 and BYF589) into the viral seed inoculum. Additionally, the intricate, multi-step, multi-variable and poorly characterised solubilisation process of the membrane glycoproteins Haemagglutinin (HA) and Neuraminidase (NA) from the surface of influenza virus by the detergent CTAB, as applied in the Agrippal manufacture platform, was comprehensively examined with the aim of enhancing process understanding by identifying the key parameters potentially affecting solubilisation efficiency and product quality. Finally, the development and optimisation of a novel GNA-binding enzyme-linked immunosorbent assay (ELISA) as an alternative replacement to the Single Radial Immunodiffusion (SRID) potency assay for quantification of HA in vaccine samples is described.
44
Ljungberg, Karl. "Variable viral genes as genetic immunogens /." Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-399-6/.
Full text
45
Mittelholzer, Camilla Maria. "Influenza virus - protection and adaptation /." Stockholm, 2006. http://diss.kib.ki.se/2006/91-7140-656-5/.
Full text
46
Lin, Shilin Cindy, and 林詩琳. "Effect of multiple annual vaccinations against influenza in the young and the elderly: a literature review." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B4299732X.
Full text
47
袁月嫦 and Yuet-sheung Carol Yuen. "Educational and promotional guidelines to improve influenza vaccine coverage of health care workers." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B43251845.
Full text
48
Shan, Songhua. "Development and evaluation of DNA vaccines in chickens against a wild bird H6N2 avian influenza virus from Western Australia /." Murdoch University Digital Theses Program, 2009. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20100211.201257.
Full text
49
Dennis, Kevin. "A mathematical model to describe haemophilus influenzae type B within Western Australia." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 1995. https://ro.ecu.edu.au/theses/1160.
Full textAbstract:
This work is primarily aimed at determining the effect that an immunisation policy Is likely to have on the incidence of Haemophllus influenzae Type B (HIB) and systematic HIB in Western Australia. There was a significant effort made to collect data pertinent to the estimation of parameter values but since HIB has only been a notifiable disease since 1992, there was a distinct lack of relevant data available. Private communication with individual’s such as Dr Jeffrey Hanna and Dr Beryl Wild resulted in practical information being obtained that was used to estimate certain parameters. The deterministic mathematical models within the thesis are extensions of existing ideas tailored to suit the needs of this thesis. Chapter one is a basic introduction to the pursuit of modelling infectious diseases with a brief description of basic epidemiology concepts. It also shows that even simple models may not deliver analytical results. Chapter two extends a model used by Angela Mclean and allows some analytical results to be obtained by first simplifying the model and then solving using standard methods to give the equilibrium distributions for the proportions of people in each state within the model
50
Buffone, Adam. "Characterization of Influenza H5N1 Nucleocapsid Protein for Potential Vaccine Design." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/20537.
Full textAbstract:
Avian influenza H5N1 causes occasional but serious infections in humans and efforts to produce vaccines against this strain continue. Current influenza vaccines are prophylactic and utilize the two major antigens, hemagglutinin and neuraminidase. NP is an attractive alternative antigen because it is highly conserved across all influenza strains, has been shown to increase the rate of viral clearance, and potential therapeutic vaccines would elicit cytotoxic T lymophcyte responses in an infected person. The NP antigen from H5N1 was characterized using a variety of physiochemical methods to gain insights into both the biological and physical properties of the antigen which are important from a regulatory viewpoint when considering therapeutic vaccines. Results obtained to date show that NP is relatively unstable and indicate that the conformation of the H5N1 NP antigen is highly dependent upon purification procedure, buffer conditions, pH and the presence or absence of RNA. These factors will need to be clearly defined and taken into consideration when manufacturing and regulating NP vaccine preparations.