Supplementation of H1N1pdm09 Split Vaccine with Heterologous Tandem Repeat M2e5x Virus-like Particles Confers Improved Cross-Protection in Ferrets

Current influenza vaccines induce strain-specific immunity to the highly variable hemagglutinin (HA) protein. It is therefore a high priority to develop vaccines that induce broadly cross-protective immunity to different strains of influenza. Since influenza A M2 proteins are highly conserved among different strains, five tandem repeats of the extracellular peptide of M2 in a membrane-anchored form on virus- like particles (VLPs) have been suggested to be a promising candidate for universal influenza vaccine. In this study, ferrets were intramuscularly immunized with 2009 H1N1 split HA vaccine (“Split”) alone, influenza split vaccine supplemented with M2e5x VLP (“Split+M2e5x”), M2e5x VLP alone (“M2e5x”), or mock immunized. Vaccine efficacy was measured serologically and by protection against a sero- logically distinct viral challenge. Ferrets immunized with Split+M2e5x induced HA strain specific and conserved M2e immunity. Supplementation of M2e5x VLP to split vaccination significantly increased the immunogenicity of split vaccine compared to split alone. The Split+M2e5x ferret group showed evidence of cross-reactive protection, including faster recovery from weight loss, and reduced inflammation, as inferred from changes in peripheral leukocyte subsets, compared to mock-immunized animals. In addi- tion, ferrets immunized with Split+M2e5x shed lower viral nasal-wash titers than the other groups. Ferrets immunized with M2e5x alone also show some protective effects, while those immunized with split vaccine alone induced no protective effects compared to mock-immunized ferrets. These stud- ies suggest that supplementation of split vaccine with M2e5x-VLP may provide broader and improved cross-protection than split vaccine alone

Influence of porosity on lipid preservation into the wall of archaeological pottery

International audiencePorosity of archaeological pottery is a key parameter used to assess its ability to trap lipids during the use of the pot and to preserve them over time. Mercury intrusion porosimetry and gas chromatography were used to study the distribution of porosity and the preservation of lipids in different chrono-cultural contexts. The data obtained show that the porosity pattern, related to the raw materials and the savoir-faire of the potters, influences the amount of lipids accumulated in the pottery. A significant overall porosity together with a high level of small pores is generally favourable for the preservation of lipids, but variations related to the environmental context are observed

Neonatal Immune Development in the Calf and Its Impact on Vaccine Response

In this article we cover the immunologic response as it develops, the components of passive immunity, and the immune response of young calves. We discuss interference from maternal immunity in the development of specific immunity and vaccine strategies for developing protection against pathogens in calves

Peripheral Leukocyte Migration in Ferrets in Response to Infection with Seasonal Influenza Virus.

In order to better understand inflammation associated with influenza virus infection, we measured cell trafficking, via flow cytometry, to various tissues in the ferret model following infection with an A(H3N2) human seasonal influenza virus (A/Perth/16/2009). Changes in immune cells were observed in the blood, bronchoalveolar lavage fluid, and spleen, as well as lymph nodes associated with the site of infection or distant from the respiratory system. Nevertheless clinical symptoms were mild, with circulating leukocytes exhibiting rapid, dynamic, and profound changes in response to infection. Each of the biological compartments examined responded differently to influenza infection. Two days after infection, when infected ferrets showed peak fever, a marked, transient lymphopenia and granulocytosis were apparent in all infected animals. Both draining and distal lymph nodes demonstrated significant accumulation of T cells, B cells, and granulocytes at days 2 and 5 post-infection. CD8+ T cells significantly increased in spleen at days 2 and 5 post-infection; CD4+ T cells, B cells and granulocytes significantly increased at day 5. We interpret our findings as showing that lymphocytes exit the peripheral blood and differentially home to lymph nodes and tissues based on cell type and proximity to the site of infection. Monitoring leukocyte homing and trafficking will aid in providing a more detailed view of the inflammatory impact of influenza virus infection

Prior infection with influenza virus but not vaccination leaves a long-term immunological imprint that intensifies the protective efficacy of antigenically drifted vaccine strains

AbstractThe role of pre-existing immunity for influenza vaccine responses is of great importance for public health, and thus has been studied in various contexts, yet the impact of differential priming on vaccine responses in the midst of antigenic drift remains to be elucidated. To address this with antigenically related viruses, mice were first primed by either infection or immunization with A/Puerto Rico/8/34 (PR8) virus, then immunized with whole-inactivated A/Fort Monmouth/1/47 (FM1) virus. The ensuing vaccine responses and the protective efficacy of FM1 were superior in PR8 infection-primed mice compared to PR8 immunization-primed or unprimed mice. Increased FM1-specific Ab responses of PR8 infection-primed mice also broadened cross-reactivity against contemporary as well as antigenically more drifted strains. Further, prior infection heightened the protective efficacy of antigenically distant strains, such as A/Brisbane/59/2006 infection followed by immunization with split pandemic H1N1 vaccine (A/California/07/2009). Therefore, influenza infection is a significant priming event that intensifies future vaccine responses against drift strains

Experimental protocol.

<p>Male Fitch ferrets (Mustela putorius furo), approximately 6 months of age were used in this study. Groups of 8 ferrets were infected intranasally with 1 x 10⁶ pfu of A/Perth/16/09, or groups of 4 to 6 ferrets were mock infected. Baseline weights and temperatures were obtained for the three consecutive days prior to challenge and on day 0 (the day of challenge). Following challenge, ferrets were monitored for change in body weight and temperature as well as clinical signs of illness on a daily basis for 5 days. Blood samples were collected for Flow Cytometry (days 0–5) and serum collected (days 0, 2 and 5) to asses antibody responses (HI assays). All ferrets were euthanized on day 2 (4 Perth/16-infected ferrets) or day 5 post-challenge (4 Perth/16-infected and all mock-infected ferrets). Viral titers were determined from nasal washes (days 0–5) nasal turbinates (days 2 and 5), BALF (days 2 and 5) and trachea (upper and lower regions; days 2 and 5). Leukocyte purification was performed from peripheral blood (days 0–5), from lymph nodes (days 2 and 5) and from BALF (days 2 and 5).</p

Clinical responses to infection.

<p>To measure morbidity the temperature (A) and body weight (B) readings of infected and control ferrets were recorded daily (days -3 to 5). Data shown are normalized to the individual animals’ weight or temperature on the day of challenge (day 0), and group averages are reported. “Mock” ferrets were infected intranasally with sterile egg allantoic fluid; “Perth/16” ferrets infected intranasally with 1 x 10⁶ pfu of A/Perth/16/09. The nasal cavities of all ferrets were washed daily with 1ml of PBS on days 0–5; and viral titers in the nasal washes (C) were determined. In addition, viral titers were determined in tissues (D); BALF, nasal turbinates (NT), upper trachea (UTr), and lower trachea (LTr). A p value of 0.05 was used as the cutoff for statistical significance (* p ≤ 0.05; ** p ≤ 0.01; † p ≤ 0.001). Error bars represent SEM.</p