A vaccine against a wide range of flu viruses has long eluded scientists, but NIAID researchers have discovered what could be the foundation of a 'universal' flu vaccine.
The traditional approach to flu vaccines is predicting which flu strains are most likely to cause human disease. Instead, Dr. Jeffery Taubenberger and his team made a "vaccine cocktail," using four of the 16 different subtypes of a flu virus protein, hemagglutinin (H). Two of them, H1 and H3, are found in human seasonal flu viruses and the other two, H5 and H7 are from avian flu viruses that can also infect people, the NIAID said in a statement.
The vaccine is made from noninfectious virus-like particles (VLPs). VLP vaccines approved for human use include those for HPV and hepatitis B.
The investigational vaccine protected 94% mice from lethal doses of a variety of influenza A virus infections. Some mice were given doses of flu virus subtypes not included in the vaccine and were protected. All of the unvaccinated mice died when exposed to virus, NIAID said in the statement.
And, Genetic Engineering & Biotechnology News reported, the team was able to show that the vaccine worked in older mice, which could be significant since existing flu vaccines are less effective in the elderly.
"These experiments suggest a promising and practical strategy for developing a broadly protective 'universal' influenza vaccine," according to the abstract. The investigators are now testing the candidate in ferrets, and if results are as promising as they were in mice, the team will start human trials.