(NEXSTAR) – The peak respiratory virus season is fast approaching, and public health officials are recommending you roll up your sleeves — or maybe just one sleeve?

When you go to get your fall booster shots, updated to fit the latest common strains of influenza and COVID-19, you’ll have the choice of getting them in one arm or two.

“There actually have been studies looking at taking the COVID vaccine and the flu vaccine together, and even in the same arm or in different arms. And the bottom line is that it really doesn’t matter,” said Dr. Andrew Pekosz, professor at Johns Hopkins Bloomberg School of Public Health.

Manar Abdalgani, an immunologist at Columbia University Irving Medical Center, said there’s one study that suggests getting both in one arm could have a benefit, but the data isn’t enough to lead to a clear recommendation.

You might want to get one on each side to spread out the soreness — but then you’ll be stuck with two sore arms instead of one extra-sore arm. Which of those scenarios is better is up to you.

While which arm you get boosted in doesn’t seem to matter much, the timing of the shots does, Pekosz said.

“It’s best to get them both taken as close as possible to each other,” Pekosz explained, “simply because studies have shown if you go in to get one and say that you’ll go in three or four weeks to get the second, many people never actually go back to the pharmacy to get that second vaccine.”

The Centers for Disease Control and Preventions says it’s safe to get both vaccines at the same time. While one study suggested getting both shots at the same time led to an 8% to 11% increase in side effects (like fatigue, headache and muscle soreness), the CDC emphasizes these side effects are mild and short-lived, and are outweighed by the benefits of getting vaccinated.