In-Depth: Benefits of combining COVID booster with flu vaccine

New studies show safety, less hesitancy
Posted at 5:53 AM, Feb 04, 2022
and last updated 2022-02-04 10:18:01-05

SAN DIEGO (KGTV) - As the COVID-19 pandemic becomes an "endemic," the idea that people could need a yearly booster is picking up steam.

That would put the COVID vaccine on par with the yearly flu vaccine. New research finds it may be a good idea to combine the two into one shot.

"I think there are all kinds of benefits in putting things together when you can," says Dr. Robert Schooley from UC San Diego Health.

Both vaccines are readily available. And in many clinics, people can get them simultaneously, but it takes two separate injections.

Dr. Schooley says combining them into one shot takes away many drawbacks to multiple vaccinations. He says people who are afraid of needles, have time constraints, or have difficulty managing numerous appointments could benefit from a combined shot.

"If you separate them ... the chances you're going to get both taken care of are much lower," Dr. Schooley says.

But combining the vaccines isn't as simple as mixing them in a needle. Studies need to prove they're safe and effective when given together.

A study published Monday, January 31, followed more than 300 people to find answers.

Participants were split into three groups: one given just the flu vaccine, one given just an mRNA COVID booster, and one given a mixture of the two.

It found people who got the mixed developed had just as many antibodies against COVID as people who received just the mRNA COVID vaccine.

Similarly, people who got the mixed shot also had just as much protection against the flu as people who received just the flu vaccine.

The study's authors say that proves the vaccines are effective when mixed.

As for safety, the study found people in all three groups had similar side effects. None reported any "serious adverse events, adverse events of special interest, and medically attended adverse events up to 6 months after injection."

"You don't want to take for granted that that won't happen," says Dr. Schooley. "So it's a good thing they're doing (these) studies."

In addition to determining the safety of combining the shots, other studies are finding a two-in-one approach makes many people more likely to get a yearly COVID booster.

A study published in November by Penn State and the Commonwealth Fund found that's especially true among minority groups.

The study surveyed 13,000 Americans. It found just 39% of Black Americans say they plan to get a yearly COVID booster. But that number jumped to 42% if the booster came as part of a shot combined with the flu vaccine.

Among Asian Americans and Pacific Islanders, 53% say they would get an annual booster shot. That number jumped to 60% if combined.

Latino American acceptance of a yearly COVID booster jumped from 46% to 51% if combined. And the percentage of Native Americans willing to get an annual booster rose from 37% to 44% when combined.

The study's author wrote that bundling the shots "may be a convenient option to increase uptake of vaccines among minorities."

There are still a lot of questions. The FDA and CDC have not yet recommended yearly boosters for COVID. They may say only high-risk groups need them. Meanwhile, COVID boosters may need to be variant specific, in the same way the yearly flu shot targets specific strains. So drug companies will have to find a way to make the combined vaccine adaptable from year to year.

Still, Moderna says they're already working on a combined COVID and flu vaccine. They hope to have it ready in time for the 2023 winter season.