Pfizer announces testing for combination vaccine to target COVID and flu

The drugmakers that developed the first COVID-19 vaccines hope to save Americans from an extra trip to the pharmacy with a single shot that targets both COVID and the flu.

Pfizer and BioNTech announed this week it is starting the first phase of is U.S. clinical trial for the first combination vaccine to tackle the two illnesses.

"We're right in the middle of actually helping develop a lot of these new combination treatments," said Dr. Kenneth Kim with Ark Clinical Research in Long Beach.

Kim will start testing Moderna's version of a combo vaccine in December. He says the mRNA technology makes it possible to code proteins for four different flu strains and two COVID variants.

"That is the beauty of the platform, that you can actually put multiple proteins on a single vaccine platform," he said.

But is there a downside? That's what researchers want to find out.

In the U.S. alone, more than 600 million mRNA vaccines have been administered. The platform has a proven track record. But what happens when you mix various types of viruses?

"You don't know whether there'll be some decrease in the efficacy. There's a possibility of different side effects that could occur because there's multiple vaccines in there," Kim said.

Scientists expect to have these answers soon to get a combo vaccine developed in time for next winter.

"What we're doing, really, is trying to prevent mortality, hospitalizations, and just really bad outcomes," he added.

The next step, Dr. Kim said, will be to see if the mRNA platform can accommodate an RSV vaccine into the mix, creating a potential high-efficacy, pan-respiratory annual booster.

"It will be so much easier to just get one vaccine instead of running around and trying to get three," Kim said.