The study, ‘Design and Characterization of a COBRA HA vaccine for H1N1 influenza viruses’, to be presented Wednesday at the World Vaccine Congress US 2016 in Washington, D.C., raises potential for a flu vaccine that covers more than a few strains at a time, and is not affected by the careful guesswork currently used to determine the strains each year's vaccine contains. "One of the problems with current influenza vaccines is that we have to make predictions about which virus strains will be most prevalent every year and build our vaccines around those predictions," said Ted 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. "What we have developed is a vaccine that protects against multiple different strains of H1N1 virus at once, so we might be able to one day replace the current standard of care with this more broadly cross-protective vaccine."
The H1N1 influenza virus caused a worldwide pandemic in 2009. When it was first detected, it was called swine flu because the virus was similar to those found in pigs, but the virus now circulates as a seasonal form of influenza. The study, published in the Journal of Virology, states that the vaccine has been developed using a technique called Computationally Optimized Broadly Reactive Antigen, or COBRA, UGA researchers Donald Carter, Christopher Darby and Bradford Lefoley, along with Ross, created nine prototype synthetic compound vaccines constructed using genetic sequences from multiple influenza virus strains.
The COBRA vaccines were designed to recognize H1N1 viruses isolated within the last 100 years, but many of the experimental vaccines produced immunity against influenza strains not included in the design. This means that scientists may be able to produce a vaccine that not only protects against recognized seasonal and pandemic influenza strains, but also strains that have yet to be discovered.
While the newly developed vaccine has only been tested with mice, success in the lab has raised expectation of a universal vaccine being developed at some point in the future. "We still have some work to do before we get a truly universal flu vaccine," said Ross. "But the COBRA vaccine we've developed for H1N1 virus subtypes is a major step in the right direction." The scientists said the strategy for designing and using the vaccines could provide a model for designing much more broad, potentially multi-year protection for people.
Additionally, the scientists emphasized the need to identify strains posing the greatest threat as the process of stopping, tweaking and restarting production of the vaccine slows down its production. With a broadly-applicable vaccine, it could be produced continuously and more cheaply, while protecting more people from infection. "What we have developed is a vaccine that protects against multiple different strains of H1N1 virus at once, so we might be able to one day replace the current standard of care with this more broadly cross-protective vaccine," said Ross in a statement.