Academic literature on the topic 'Single radial haemolysis'

Nineteen children with cystic fibrosis and aged between 5 and 13 years were randomized to receive two doses at monthly intervals of either a split-virion influenza vaccine (MFV-Ject, Institut Merieux) or a sub-unit vaccine (Fluvirin, Evans). In those completing the study, there was a satisfactory serological response. There was no statistically significant difference between the immunogenicity of the two vaccines as evaluated by haemagglutination inhibition or single radial haemolysis tests. The incidence of local side-effects was similar in the two groups.

SummaryThirty-one ponies immunized with inactivated virus vaccine containing A/equine/Miami/63 (H3N8) virus and six seronegative ponies were experimentally challenged with the homologous virus strain. All G unvaccinated ponies and 11 out of 31 vaccinated ponies became infected. A clear relationship between pre-challenge antibody, measured by single radial haemolysis (SRH), and protection was demonstrated as judged by virus excretion, febrile responses and antibody responses. Those ponies with SRH antibody levels > 74 mm2 were completely protected against challenge infection by the intranasal route.

Influenza B is responsible for a significant proportion of the global morbidity, mortality and economic loss caused by influenza-related disease. Two antigenically distinct lineages co-circulate worldwide, often resulting in mismatches in vaccine coverage when vaccine predictions fail. There are currently operational issues with gold standard serological assays for influenza B, such as lack of sensitivity and requirement for specific antigen treatment. This study encompasses the gold standard assays with the more recent Pseudotype-based Microneutralisation assay in order to study comparative serological outcomes. Haemagglutination Inhibition, Single Radial Haemolysis and Pseudotype-based Microneutralisation correlated strongly for strains in the Yamagata lineage; however, it correlated with neither gold standard assays for the Victoria lineage.

SUMMARYEquine influenza vaccines containing inactivated whole virus and Carbomer adjuvant stimulated higher levels and longer lasting antibody to haemagglutinin in ponies than vaccines of equivalent antigenic content containing aluminium phosphate adjuvants. Five months after the third dose of vaccine containing Carbomer adjuvant, ponies were protected against clinical disease induced by an aerosol of virulent influenza virus (A/equine/Newmarket/79, H3N8). In contrast ponies which received vaccine containing aluminium phosphate adjuvant were susceptible to infection and disease. There was an inverse correlation between prechallenge levels of antibody detected by single radial haemolysis (SRH) and duration of virus excretion, pyrexia and coughing. All ponies with antibody levels equivalent to SRH zones of ≥ 154 mm2 were protected against infection and all those with levels ≤ 85 mm2 were protected from disease.

Les virus influenza équin (EIV) et herpèsvirus équin-1 (EHV-1) sont fréquemment décrits dans de nombreux pays et sont deux pathogènes endémiques au sein de la population équine française. Ces maladies infectieuses ont d’importantes conséquences aussi bien au niveau santé et bien-être animal qu’en terme d’impact économique. La lutte contre ces virus repose essentiellement sur la mise en place de mesures préventives telles que la vaccination. Malgré cela, les épizooties d’EIV et d’EHV-1 sont régulièrement observées en France et dans le monde. Les anticorps neutralisants, synthétisés en réponse à l’infection ou après immunisation, représentent une ligne de défense majeure. L’amélioration des vaccins et l’enrichissement du panel d’outils de mesure des anticorps neutralisants peuvent constituer un apport stratégique dans la lutte contre ces virus. Afin d’améliorer l’efficacité de la réponse vaccinale en amplitude et dans le temps, l’utilisation d’adjuvants constitue une des voies de recherche prometteuse. Ce travail de thèse a consisté, dans un premier temps, à établir la preuve de concept de l’utilisation de l’iPPVO en tant qu’adjuvant innovant in vivo chez le cheval dans le cadre de la vaccination contre l’EIV. Pour cela, les anticorps ont été mesurés par SRH, méthode pour laquelle des corrélats de protection sont associés au taux d’anticorps mesuré. L’ajout d’iPPVO lors de la vaccination a permis d’augmenter significativement le niveau d’anticorps contre l’EIV ainsi que le niveau de protection des chevaux jusqu’à 6 mois après l’immunisation. Dans un second temps, une méthode de mesure des anticorps anti-EIV faisant appel à l’impédancemétrie a été développée afin d’enrichir les méthodes actuelles et faciliter l’analyse à haut débit. Cette méthode de séroneutralisation a présenté une bonne corrélation avec les valeurs de titres SRH. Une seconde étude a testé, le potentiel adjuvant de l’iPPVO in vivo chez le cheval dans un modèle de vaccination contre l’EHV-1,4. La réponse en anticorps mesurée par séroneutralisation a été augmentée jusqu’à 5 mois suivant l’immunisation. Enfin, des résultats préliminaires sur le mécanisme d’action de l’iPPVO sur les cellules mononucléées du sang périphérique a permis de mettre en évidence l’importance de la réponse interféron
Equine influenza virus (EIV) and equine herpesvirus-1 (EHV-1) are frequently described in many countries and are two endemic pathogens in the French equine population. These infectious diseases have important consequences both in terms of animal health and welfare and in terms of economic impact. The fight against these viruses is essentially based on the implementation of preventive measures such as vaccination. Despite this epizootics of EIV and EHV-1 are regularly declared in France and throughout the world. Neutralising antibodies, synthesised in response to infection or after immunisation, represent the main line of defence against these viruses. Improved vaccines and a wider range of tools to measure neutralising antibodies can be a valuable strategy in the fight against these viruses. In order to improve the efficacy of the vaccine response, both in magnitude and duration, the use of adjuvants is one way to improve immunogenicity. This thesis consisted, in the first instance, in establishing the proof of concept of the use of iPPVO as an innovative adjuvant in vivo in horses in the context of vaccination against EIV. For this purpose, antibodies were measured by SRH, a method for which the correlates of protection are well defined. The addition of iPPVO at vaccination significantly increased the antibody level to EIV and protection in horses up to 6 months after immunisation. In a second step, a new method for measuring EIV antibodies in serum based on impedancemetry was developed to improve on current methods and facilitate high throughput analysis. This neutralisation test correlated well with SRH test. Another study was performed, which demonstrated the adjuvant potential of iPPVO in horses during vaccination against EHV-1,4. The antibody response measured by serum neutralisation increased up to 5 months after immunisation. Finally, preliminary results on the mechanism of action of iPPVO on peripheral blood mononuclear cells demonstrated the importance of the interferon

Abstract Complement activation plays an important role in the inflammatory response and in the pathogenesis of many infectious diseases. Simple assays such as radial immunodiffusion and nephelometry are available for measuring concentrations of native complement components in biological fluids. These assays have focused on C4, C3, and factor B as participants in different phases of the complement cascade reaction. However, since hypercatabolism and increased synthesis of complement components such as C3 and factor B may occur concurrently, the information related to in vivo complement activation which may be obtained from measurements of native complement components is limited. In addition, measurements of native complement components may be affected by the presence of activation products in the sample if not properly collected and stored. On the other hand, direct measurement of generated activation products by newer techniques can provide a reliable indication of ongoing complement activation. Such measurements may be used to monitor disease activity and the effect of therapeutic treatment. They do not, however, provide information about the functional state of the complement system. When such information is desirable, functional tests, such as haemolytic assays (see Chapter 2) or assays measuring the opsonic capability (1) of the system, should be used.