Combination COVID-19 and Influenza Vaccine Under Development

With predictions that COVID-19 boosters will be needed each year, some companies are working on combining those with the annual influenza (flu) vaccine in a single injection given each fall. Pharmaceutical companies Moderna and Novavax have already announced plans to work on a combination vaccine, but Moderna’s CEO says it will not be ready until 2023.

However, there are technical challenges to creating a combination vaccine. One is that different scientific approaches have been used for the two types of vaccines. “Right now, the influenza vaccine is a different platform,” said Anna Durbin, MD, director of the Center for Immunization Research at Johns Hopkins University. The most widely used flu vaccines in the U.S. contain inactivated (killed) or attenuated (weakened) virus to trigger an immune response in the body, which differ from mRNA (messenger RNA) vaccines that teach the body’s cells how to make proteins that trigger immune responses.

In addition to differences in technology, another challenge is that the most common influenza vaccine in the U.S. is quadrivalent, meaning it is designed to protect against four different flu viruses. “This means the combined influenza/COVID vaccine would also likely need to be quadrivalent or at least trivalent. That makes the vaccine more complicated,” said Dr. Durbin.

Similarly, the rise of new COVID variants may introduce challenges to vaccine development.