A new study shows that individuals immunized six years earlier with an MF59 adjuvanted H5N3 (clade 0) vaccine mounted a protective immune response seven days after a single immunization with an H5N1 (clade 1) vaccine containing the Novartis proprietary adjuvant MF59. The immune response was broadly cross reactive and covered all H5N1 clades known to date. These data were presented at the Third European Influenza Conference in Vilamoura, Portugal.
Responses were seen even against viral strains not included in either vaccine suggesting proactive priming strategies with an MF59 adjuvanted-H5 vaccine may have the potential to help save lives in an avian influenza pandemic situation.
"These data highlight the potential for priming the public against an avian influenza of pandemic proportion with the MF59 adjuvant. The results indicate that regardless of which avian strain individuals are originally primed with, they are quickly protected against a broad range of avian strains following their MF59-adjuvanted booster vaccine, even strains they were not initially inoculated against," said study investigator Iain Stephenson M.R.C.P., Infectious Diseases Unit, University Hospitals Leicester and Department of Inflammation, Infection and Immunity, University of Leicester, UK.
"These results potentially provide a rationale to prevent pandemic influenza by proactively immunizing the public with stockpiled pre-pandemic vaccines containing MF59," Dr Stephenson added.
According to the trial results, healthy adults primed with an MF59-adjuvanted H5 vaccine at least 6 years ago, and boosted with the Novartis pre-pandemic vaccine AFLUNOV (7.5microgram MF59-adjuvanted A/Vietnam/1194/2004 clade 1 H5N1), showed a protective cross-reacting antibody response to diverse H5N1 virus variants. Response was seen within 7 days and results were significantly higher (P< 0.05) at 14 days than those primed with a un-adjuvanted vaccine. In addition, these study results suggest primed individuals would only need one dose of an MF59-adjuvanted vaccine in a pandemic situation to elicit initial protection reducing overall response time, and potentially the spread of the virus.
"These findings show that priming subjects with the Novartis proprietary adjuvant MF59 included in AFLUNOV can induce long-lasting immune-memory and further supports a proactive priming strategy as part of pandemic preparedness efforts" said Dr. Joerg Reinhardt, CEO of Novartis Vaccines and Diagnostics, a division of Novartis. "Novartis Vaccines is committed to putting forth the most effective vaccine possible to help protect the global public against a possible pandemic situation."
An influenza pandemic occurs when a new influenza strain emerges (one to which humans have no immunity), mutates and spreads globally as a virus. Although it is not possible to predict the actual pandemic influenza strain, global health authorities have identified H5N1 avian influenza as a strain with the greatest pandemic potential in humans. H5N1 is currently circulating in birds and has caused serious illness in more than 380 people worldwide with a mortality rate, among people known to have been infected, of greater than 60 per cent.
The purpose of pre-pandemic vaccination is to prime the immune system to better defend against infections from an H5N1 influenza virus and is intended for use before the World Health Organization (WHO) declares an influenza pandemic. AFLUNOV is the only pre-pandemic vaccine in development with an extensively-studied adjuvant, MF59, that is supported by more than 10 years of clinical safety data and commercial use.
Novartis Vaccines is working closely with government and regulatory officials worldwide to support pandemic preparedness efforts, including engaging in government contracts to provide H5N1 vaccines for stockpiling. The company has also been involved in discussions to educate government agencies about the benefits of proactive use of pre-pandemic vaccination in pandemic preparedness planning efforts.
Novartis Vaccines is supportive of the WHO's leadership role in global pandemic planning as discussed in the organization's "THE WORLD HEALTH REPORT 2007: Global Public Health Security in the 21st Century." The WHO is a key global hub for pandemic preparedness, ensuring cohesion and coordination among all players involved, including the industry, governments of both developed or developing countries and their populations.
The company also recognizes the importance of pandemic influenza preparedness planning within the business community in an effort to protect the global economy. With this commitment, Novartis Vaccines is working with business leaders to support their continuity planning for pandemic preparedness.