A vaccine called COBRA vaccine that protects against multiple co-circulating strains of H3N2 influenza isolated over five seasons has been developed.
- A vaccine that protects against all co-circulating strains of H3N2 viruses has been developed.
- This more broadly cross-protective vaccine may replace seasonal vaccine.
- A methodology called computationally optimized broadly reactive antigens (COBRA) was used to design novel hemagglutinin (HA) vaccine immunogens.
Using a technique called Computationally Optimized Broadly Reactive Antigen, or COBRA, UGA researchers Terianne Wong, James Allen, Anne Bebin-Blackwell, Donald Carter, along with Ross, created 17 prototype vaccine candidates constructed using genetic sequences from multiple influenza virus strains.
Evolving H3N2 influenza virus
The H3N2 influenza viruses evolve rapidly each year and the viruses at the start of a flu season may be well matched to the vaccine, but a few months later they may have drifted and able to evade the vaccine-induced immune response.
"One of the problems with current influenza vaccines is that the vaccine takes over six months to produce so vaccine manufacturers have to start well before flu season begins. Educated guesses are made by public-health authorities about which virus strains will be most prevalent during the upcoming flu season," said Ted M. Ross, director of UGA's Center for Vaccines and Immunology and Georgia Research Alliance Eminent Scholar in Infectious Diseases in the College of Veterinary Medicine. "They look at which flu viruses are circulating in the Southern Hemisphere during their winter months (May-September), as a preview for what we in the Northern hemisphere could see in our upcoming flu season each year. This year, it was a particularly bad flu season in Australia with H3N2 strains being most prevalent. What our group has developed is a vaccine that protects against all co-circulating strains of H3N2 viruses, so we might be able to one day replace the seasonal flu vaccine with this more broadly cross-protective vaccine."
This research is part of a broader effort to create a universal influenza vaccine, which would protect against all strains of the virus.
"This is progress, but we still have work to do before we get a truly universal flu vaccine," Ross said. "We need to determine how many seasons this H3 COBRA vaccine will protect against all H3N2 viruses into the future in all populations of people."
References:
- Terianne M. Wong1, James D. Allen et al. COBRA HA Elicits Hemagglutination-Inhibition Antibodies Against a Panel of H3N2 Influenza Virus Co-Circulating Variants, Journal http://dx.doi.org/10.1128/JVI.01581-17