Encouraging Findings Point to a Universal Flu Vaccine

Fresh off the heels of research revealing that this year’s flu vaccine was only effective in one out of 4 people, investigators are now taking steps to develop a universal vaccine.

The flu vaccine is reinvented every year in order to adjust to possible mutations that could have occurred within the virus. However, it typically only protects against 3 specific strains including H1 and H3 influenza A viruses and influenza B virus strains. Lead authors Taia Wang, MD, PhD, and Jad Maamary, a postdoctoral associate, along with colleagues from The Rockefeller University made discoveries that could lead to a vaccine which shields against a broader range of strains.

“The new mechanism we have uncovered, by which a vaccine containing sialylated antibodies elicits broadly protective antibodies, could potentially be harnessed to reduce the tremendous morbidity and mortality caused by seasonal influenza virus infections,” Wang, an instructor in clinical investigation, said in a news release.

The body produces an immune response when one side of an antibody connects to an antigen and the other (Fc region) to immune cells. According to the report published in Cell, the researchers built off of the understanding that modifying the Fc region and immune cells interaction would cause an alternative response.

Healthy participants were vaccinated with a seasonal flu vaccine that had an inactivated strain of the H1N1 virus. Blood samples and chemical changes, such as those against the hemagglutinin protein by antibodies, were examined to determine key immune responses. The team discovered an increase in sialylated antibodies in the Fc region which suggested a better response to the vaccine.

“When we immunized mice with just the H1 protein from one strain or with the sialylated complexes containing the same viral protein, we found both offered equal protection against the same strain of flu,” Maamary said. “However, when we exposed them to strains expressing different versions of the H1 protein, only the sialylated immunizations offered protection.”

The findings suggest that a vaccine with sialylated antibodies would be able to guard against more than 3 strains, creating a more protective counteragent. The authors are hopeful that these are the initial steps towards a universal flu vaccine.

“We are now looking into applying this strategy toward improving existing vaccines; ideally, this would result in a vaccine that provides lifelong immunity against flu infections,” Wang concluded.