Will there be a single shot combining flu, COVID-19 booster vaccines?

With COVID-19 booster shots expected to become as routine as an annual flu vaccine, a single shot combining both is currently being tested.

Pfizer announced a study is underway by its German partner, BioNTech, of a combination of the companies’ updated COVID-19 booster shot that became available in the United States in early September and a Pfizer flu vaccine that’s in development. Both products utilize mRNA technology.

The aim is to efficiently “address two severe respiratory diseases with one vaccine,” according to a news release from Pfizer.

“The flexibility and manufacturing speed of the mRNA technology has demonstrated that it is well-suited for other respiratory diseases,” Annaliesa Anderson, Pfizer senior vice president and chief scientific officer, vaccine research and development, said in a statement.

The company thinks a combination vaccine “could simplify immunization practices against these two respiratory pathogens, potentially leading to better vaccine uptake for both diseases,” Anderson said, noting that the flu causes thousands of deaths and hospitalizations worldwide every year.

Americans have been urged to get both an annual flu shot and an updated COVID-19 booster shot known as a bivalent vaccine because it’s targeted at the currently circulating versions of the omicron variant of the COVID-19 in addition to the original strain of the coronavirus.

The shots can be given at the same time, but less than a quarter of Americans are estimated by the Centers for Disease Control and Prevention to be covered against the flu, and just 7.3% have gotten an updated COVID-19 booster shot.

Annual flu shots are available for children as young as 6 months old, but the updated COVID-19 booster is currently authorized only for those 5 and older, although the CDC said in September that “at least one bivalent vaccine for children aged 6 months to 4 years may be authorized later in the fall.”

In Utah, less than 8% of all residents are considered fully vaccinated against COVID-19, meaning they’ve gotten the updated COVID-19 booster shot or, if they’re under 5 but at least 6 months old, have completed the initial coronavirus vaccine series.

The low uptake is despite a push from President Joe Biden on down to get people vaccinated against both the flu and the coronavirus in anticipation of a surge in respiratory viruses this winter. Influenza and other respiratory viruses had all but disappeared while masking and other precautions were being taken against COVID-19.

Pfizer said the randomized study of the combined vaccine, sponsored by BioNTech, is being conducted in the United States, and plans are to enroll 180 volunteers 18 through 64 years old to evaluate “safety, immunogenicity, and optimal dose level.” The company said there will be a six-month follow up period for each participant.

Two other companies that make COVID-19 vaccines, Moderna and Novavax, are also developing a combined COVID-19 and flu vaccine, Reuters reported. Moderna, which also makes an mRNA-based COVID-19 vaccine and updated booster shot, told the news service in September 2021 that work was underway on a combined shot.