A study published this week in the Proceedings of the National Academy of Sciences of the United States of America shows that Aflunov, the Novartis investigational pre-pandemic avian influenza vaccine formulated with Novartis' proprietary MF59 adjuvant, can elicit a broadly cross-reactive immune response covering all known H5N1 antigenic variants, even when that booster dose is administered six years after the initial priming dose.
The data show that the Novartis investigational adjuvanted vaccine elicited a long-lasting immune response that could be rapidly boosted following a single dose of the vaccine. This may provide public health officials additional flexibility to help protect citizens well in advance of an avian influenza pandemic. The study also showed that the adjuvanted vaccine created an immune memory not only against the H5N1 strain contained in the vaccine but also provided cross-protection against several other H5N1 strains.
"These data reinforce the potentially broad applicability of the MF59 adjuvant and the role it can play in pandemic preparedness efforts around the world," said Andrin Oswald, CEO of Novartis Vaccines and Diagnostics. "Cross-reactivity is an important element for a pre-pandemic vaccine given that variations are a common feature of emerging influenza strains. We will use these new insights, as well as our strong leadership position in cell based flu manufacturing, as part of our efforts to develop a vaccine against the current swine flu outbreak."
"The findings published about the H5N1 vaccine suggest a way forward for the present swine flu outbreak," added Rino Rappuoli, head of Research at Novartis Vaccines. "We are working closely with the World Health Organization, US Centers for Disease Control and Prevention (CDC), PAHO and other government agencies worldwide on developing a strong and effective response to the outbreak."
These data are part of several new studies presented this week at the Third International Conference on Influenza Vaccines for the World (IVW) in Cannes, France. Selected Aflunov data were previously presented in September 2008 at ESWI in Portugal, and announced at that time. Aflunov has not been tested on swine flu and has not been approved for sale in the US, Europe or other markets. A phase-II study has also demonstrated that Aflunov provided a protective immune response in children as young as six months to 17 years of age. It is the first and only -pre-pandemic avian vaccine with a good safety profile and which is effective in building an immune response as early as 6 months of age.
"To have a pre-pandemic vaccine that can produce a protective immune response in children as young as six months of age, as well as seniors is essential," said Timo Vesikari, professor of virology and pediatrics and director of the Vaccine Research Center at the University of Tampere, Finland. "Children are not only at the biggest risk of complications from influenza, but they have been identified as the prime population for spreading the virus to all ages. We need to ensure that they are protected against a potential pandemic, which can strike at any time."
In a third study presented at IVW, Aflunov demonstrated that it could potentially be used to prime the general public against a potential influenza pandemic through a flexible dosing regimen, which would allow public health officials to immunize their citizens by administering the vaccine well in advance of a potential outbreak. The trial showed that a single priming dose of the vaccine was sufficient to develop immune memory in more than 90 per cent of healthy adults, which could then be boosted one year later with either the same or a different strain of the avian influenza virus.
MF59 is the only flu adjuvant in a pre-pandemic programme with an established safety profile, supported by more than 10 years of clinical safety data and more than 40 million doses of commercial use in Europe. The adjuvant has been studied in clinical trials involving more than 26,000 people, including children, and has been licensed for use in people 65 years of age and over in the seasonal influenza vaccine, Fluad, since 1997 in the European Union. Fluad is not licensed for sale in the US.