Every year, scientists and health officials try to predict which flu strains are upcoming in order to create an effective vaccine, but these efforts are met with varying levels of success. Scientists at UCLA now claim to have used a new approach to vaccine development to create a vaccine candidate that induces strong immune response in animal studies. Their research was published today in Science.
The new vaccine relies on an understanding of the interactions between the virus and interferons. Many viruses, including influenza, have evolved strategies to evade detection by interferons and limit production of long-term defense.
The team spent four years searching the influenza virus’s genome for its anti-interferon properties. After defining the function for every amino acid in the genome, they deactivated sequences that prevent interferon induction. In total, eight locations were deactivated by changing one amino acid at a time.
An engineered virus with the anti-interferon sequences deactivated was used to vaccinate animals. The vaccine appeared to be safe and effective in these trials.
"By disabling these interferon-evasion functions, the engineered virus is weakened in typical hosts," said Yushen Du, the study's first author, who recently earned her doctorate at UCLA. "At the same time, however, due to interferon stimulation, the engineered virus generates very strong immune responses."
The team plans to test the vaccine in animals with two strains of influenza before moving to human clinical trials. This method may also serve as a template for creating vaccines for other diseases.
Image: UCLA scientists developed a new technique to identify and eliminate the virus's defense mechanisms. Image courtesy of the National Institute of Allergy and Infectious Diseases/NIH.