The first RSV vaccines are coming in August. Who should get one?

Between 60,000 and 160,000 adults 65 and older are hospitalized each year with severe symptoms caused by RSV, and 6,000 to 10,000 die. About 58,000 to 80,000 children under age 5 are hospitalized each year, and 100 to 300 die, according to the U.S. Centers for Disease Control and Prevention. 

The approval of the new shots — two alternatives for adults 60 and older, and one for children 2 and under — could soften the blow of another so-called “tripledemic” of COVID, flu and RSV for those at risk of getting the sickest. There’s no antiviral drug or other treatment for RSV beyond trying to manage the symptoms.

“This is a really wonderful development for public health,” said Dr. Daniel Kwan, medical director of Dignity Health-Go Health, a network of urgent care clinics in the Bay Area. “RSV is not a disease you can treat necessarily. So the best way is to prevent it, and now we have a way to do that.”

The rollout of the new RSV shots is expected to be done on a much smaller scale than that of the COVID vaccines or annual flu shot because only the very young and older adults are approved to get them. 

What are the new vaccines?

Two RSV vaccines have been approved for adults 60 and older: Arexvy, made by GSK; and Abrysvo, made by Pfizer. The U.S. Food and Drug Administration approved them in May.

The new shot for children is not a vaccine, but essentially functions as one. It is a monoclonal antibody, nirsevimab, that gives the immune system protection against the virus. It is made by AstraZeneca and Sanofi, under the brand name Beyfortus, and was approved by the FDA in July for babies and toddlers up to 2 years old.

There’s already an existing monoclonal antibody for some infants, palivizumab, but it’s limited to only the highest-risk babies — those born prematurely, or with congenital heart disease or chronic lung disease — and is given by injection every month during respiratory season. So the new shot, which is a one-time injection and lasts longer, is expected to be more accessible and available to a broader group of babies.

Who should consider getting one?

Older adults with underlying health conditions: The GSK and Pfizer vaccines are FDA-approved for adults 60 and older. But unlike the broad recommendation the CDC gives for flu and COVID vaccines, the agency says the decision to get an RSV vaccine should be based on “shared decision-making” between individuals and their doctors. This means it falls into a gray area — the data is not strong enough to recommend it for everyone who’s eligible, but there’s enough potential benefit that eligible people should have the opportunity to get it, said Dr. Jeffrey Silvers, medical director of pharmacy and infection control at Sutter Health.

If you’re 60 or older and have underlying health issues — like a lung or heart condition, asthma, diabetes, or are immunocompromised — talk to your doctor about getting vaccinated. This is especially true if you’re medically frail or live in a nursing home or other congregate living situation, where respiratory viruses spread more easily. 

“There’s not a magic cutoff at age 60,” said Dr. Lisa Winston, the hospital epidemiologist at Zuckerberg San Francisco General Hospital and a professor of medicine at UCSF. “The older you get, the higher your risk. If I had a patient who was much older or who was frail, in poor health, their risk is higher. It’d be reasonable to more strongly recommend the vaccine.”

Infants and toddlers: The FDA approved the new monoclonal antibody shot for infants entering their first RSV season and toddlers up to age 2. But the CDC has not formally recommended it. Vaccine advisers for the CDC are scheduled to meet Aug. 3 to decide who should receive it, and a CDC recommendation will likely follow suit. Some infectious disease doctors anticipate the shot will be recommended for most infants and toddlers 2 and under. 

Pregnant women, potentially: An FDA panel in May approved the Pfizer RSV vaccine for pregnant women, who would pass protection onto their babies. But the full FDA has not yet approved the vaccine for pregnant women, so this is something to keep an eye on. An FDA decision could come in August. 

How well do the vaccines work?

The two vaccines for older adults use different types of technology but are similar in safety and efficacy, rated roughly 80% effective at preventing lower respiratory tract disease associated with RSV.

The GSK vaccine, Arexvy, was 83% effective at preventing RSV-associated infection during the first RSV season; that dropped to 75% by the second season, according to a CDC analysis released July 21. The late-stage trials included about 25,000 healthy adults age 60 and older in 17 countries.

The Pfizer vaccine, Abrysvo, was 89% effective at preventing RSV-associated infection during the first RSV season; that dipped to 84% by the second season. The late-stage trials included nearly 27,000 healthy adults 60 and older in seven countries.

For both vaccines, the side effects for most clinical trial participants were similar to those of many other vaccines, including sore arm, fatigue and body aches. In both trials combined, there were six cases, out of tens of thousands of trial participants, of neurological disorders, including Guillain-Barré syndrome, a rare event that can cause nerve damage. Guillain-Barré occurs at a low rate in the population as a whole, and it’s not clear whether the cases in the trials were related to the vaccines. The FDA is requiring both vaccine manufacturers to monitor this going forward.

Experts cautioned against picking one over the other based on the clinical trial results because the studies were done at slightly different times and had different follow-up periods, so it’s not an apples-to-apples comparison.

“They looked like they were both quite effective,” Winston said.