A new RSV vaccine for those 60 and older is now available at pharmacies along with an updated COVID-19 vaccine and seasonal flu shots.

It might be tempting to get all three at once, but Northeastern experts recommend that those eligible for the RSV vaccine space it out from the COVID and flu shots by a week or two to maximize its effectiveness and minimize side effects.

“The common strategy is to get the flu and updated COVID shots on the same day, in different arms, and then two weeks before or after that get your RSV vaccine,” says Brandon Dionne, an associate clinical professor in Northeastern’s School of Pharmacy and Pharmaceutical Science.

“That’s probably the optimal strategy at this point until we have more data on coadministration” with the COVID vaccine, he says.

The FDA on Sept. 11 approved updated COVID-19 vaccines in time for the fall and winter. The Moderna and Pfizer vaccines are so-called monovalent vaccines designed to protect against the Omicron variant XBB.1.5 that circulated in the spring and summer.

There’s no data available on whether the RSV vaccine could impact the effectiveness of the updated COVID shots, Dionne says.

There’s some indication that giving the RSV and flu shots at the same time could lower overall antibody response, but not below the minimal acceptable level for provoking an immune response, he says.

If somebody lives in a rural area and has to travel long distances to get their shots, there’s no harm in getting all three at once, Dionne says.

The risk of RSV

RSV is a respiratory illness that poses increased risk of pneumonia and other dangers in older people, which is why it is recommended for those 60 and over and also for younger people with compromised immune systems.

Babies are also more susceptible to RSV. In July, the FDA approved a monoclonal antibody treatment for infants in their first RSV season and for vulnerable children up to 24 months.

Neil Maniar, professor of public health practice, recommends getting the RSV shot before the flu and COVID vaccines.

The RSV vaccine “is longer lasting and you want to build up immunity” to what can be a serious respiratory illness, Maniar says.

Mansoor Amiji, distinguished professor in Northeastern’s School of Pharmacy and Pharmaceutical Sciences, says people who have a mild or no reaction to the RSV vaccine can go ahead and get their flu and COVID shots the next week.

“I think one week is sufficient” for healthy people who aren’t experiencing a lot of side effects, he says.

RSV vaccine side effects

Side effects to the new RSV shot include fatigue, fever, headache, nausea, diarrhea and muscle or joint pain, as well as swelling at the vaccination site, the CDC says.

The reason for this is an adjuvant, or chemical compound, in the RSV vaccine that’s designed to boost immune response in older people, Dionne says.

“The general purpose (of adjuvants) is to increase immune response so you have a higher production of antibodies to the amount of antigen you have in the vaccine,” Dionne says. 

That can result in increased side effects, he says, adding that “we see the same thing with the shingles vaccine.”

The Northeastern experts say it could be a good idea to plan on a light workload the day after getting an RSV vaccine to see how it affects you.

Is it too early to get your shots?

They recommended getting the flu and COVID vaccines together any time from the end of September through mid-October.

Getting the flu vaccine in October provides about five months of protection, Dionne says.

“Fall is a good time,” starting with the end of September and early October, Amiji says.

Getting inoculated at that time will provide protection for when people get together for the holidays in November and December and infections start to peak, he says.

“It takes a couple of weeks to really build up immunity,” Maniar says.

“If you were to get the flu and COVID vaccines in early October, by mid-October you have a good dose of immunity to both COVID and to the flu that is likely going to last you through the holiday season and through the new year,” he says.

Cynthia McCormick Hibbert is a Northeastern Global News reporter. Email her at c.hibbert@northeastern.edu or contact her on X/Twitter @HibbertCynthia.