Current flu vaccines are tailored for the flu of the season, with mixed results in efficacy. A new vaccine candidate is currently being studied at the Perelman School of Medicine, and an initial study on mice elicited a strong antibody response to flu viruses, protecting them from infection. This new vaccine could uniquely serve as a universal flu vaccine, as opposed to the seasonal flu vaccines updated every year.
Each year, flu vaccines are updated with a structure on the surface of flu viruses, called the hemagglutinin (HA) stalk, or HA protein. Each flu season, vaccines are designed for the current HA protein. Current vaccines are directed at the outermost region of the HA protein, making prevention incomplete.
The vaccine currently being studied uses mRNA molecules that are taken up by the immune system and translated into copies of the HA protein, mimicking a flu infection and eliciting an antibody response. Rather than just targeting the outermost region of the HA protein, antibodies hit the lower region of the HA, a favored target for universal flu vaccines.
“This vaccine was able to do something that most other candidate flu vaccines have not been able to do,” says study co-senior author Drew Weissman, a professor of infectious diseases. “It was able to elicit protective responses against a conserved region that offers broad protection.”
The study’s details are published in Nature Communications. Researchers will focus their next steps on primates and human clinical studies within two years.
Source: University of Pennsylvania