CDC advisory panel opts for a go-slow approach on expanding usage of RSV vaccines

Makers of RSV vaccines for older adults saw their plans to try to expand usage hit a significant hurdle on Wednesday, when an expert committee that advises the Centers for Disease Control and Prevention on vaccines recommended changes that will likely see fewer older adults qualify for insurance coverage for these products.

In a related move, the Advisory Committee on Immunization Practices opted not to make a recommendation yet on use of GSK’s Arexvy vaccine in adults 50 to 59, saying the committee didn’t have enough data with which to make such a recommendation. Earlier this month the Food and Drug Administration approved use of the GSK vaccine to include adults in their 50s at high risk of developing severe disease if they contract respiratory syncytial virus, or RSV. When it was initially approved in May 2023, its use was restricted to people 60 and older.

The decision is a blow to GSK, which has been racing to secure market share in a field that now includes two competitors, Pfizer and Moderna. To that end, GSK used a priority review voucher to speed its age extension application through the FDA approval process. The agency is currently reviewing an application from Pfizer to extend the license for its RSV vaccine, Abrysvo, to include adults 18 and older who have health conditions that put them at risk of severe illness from RSV infection.

In a statement, GSK said it will continue to generate data on the vaccine to add to what it called “the existing robust clinical data package,” to help guide future policy making decisions.

Without a recommendation for use from the ACIP and the CDC, insurance companies are unlikely to cover the cost of the GSK vaccine for people in their 50s. And at nearly $300 a dose — not including administration fees — those individuals may be reluctant to pay out of pocket.

The final decision on vaccination use policy rests with the CDC director, Mandy Cohen. Late Wednesday the CDC issued a statement adopting the recommendations the ACIP had approved about an hour before.

“The CDC has updated its RSV vaccination recommendation for older adults to prioritize those at highest risk for serious illness from RSV,” Cohen said in the statement. 

In particular, the work group suggested it needs information on how adults in their 50s who have immunocompromising conditions react to the vaccine — what kind of antibody responses it generates — more data on whether additional shots will boost protection that has waned. Some of the data to date suggest the reaction to booster shots is not as powerful as the response to the initial vaccine. ACIP member Sarah Long, a pediatrics professor at Drexel University College of Medicine in Philadelphia, worried that if boosting isn’t effective, giving the RSV vaccine too soon might squander a tool that could be more needed later in life.

Long and others on the committee worried that given the possible link to GBS, the risk-benefit ratio for people in their 50s may not favor vaccination in the way it does in older adults. 

RSV vaccines for older adults are new. The first two, from GSK and Pfizer, were approved last spring and were rolled out for the first time in the autumn. Initially licensed only for adults 60 and older, the ACIP opted last June not to make a universal recommendation for their use, in the way that everyone is urged to get an annual flu shot. Instead, it suggested people who were eligible could get one of the vaccines, but should first talk to a health care provider to weigh the risks and benefits of getting vaccinated.

That approach, called shared decision-making, made sense to a committee that was reluctant to urge everyone 60 and older to get a shot, given that there are concerns that a small number of people who get the Pfizer and GSK vaccines — particularly the former — may develop Guillain-Barré syndrome, a form of progressive paralysis from which people normally recover, but after an extended period of hospitalization. There were no reports of Guillain-Barré syndrome among people in the clinical trials that led to the approval of Moderna’s RSV vaccine, mResvia, which was just approved by the FDA at the end of May.

Doctors and pharmacists complained about the shared decision-making recommendation, indicating they didn’t always know how to advise patients. There are concerns that the recommendation may have depressed uptake of the vaccine.

So the ACIP’s RSV work group proposed changing the recommendation in two ways, both of which were unanimously accepted by the full committee. In a vote of 11 to 0, the committee recommended that people aged 75 and older should get an RSV shot, if they have not yet had one. While it’s known the protection of these vaccines wanes with time, it’s not yet clear what the optimal cadence for revaccination is. So at present there is no recommendation for people who were vaccinated already to get another RSV shot.

In the second vote, the committee recommended that people aged 60 to 74 who have health conditions that put them at high risk of severe illness from RSV should also get the vaccine. People aged 60 to 74 who do not have one of the health conditions named could still get the vaccine, if they wish. But without an ACIP/CDC recommendation, they would have to pay out-of-pocket, committee chair Helen Keipp Talbot noted.

The health conditions listed include lung disease, cardiovascular disease, diabetes with end organ damage, severe obesity, neurological or neuromuscular conditions, advanced chronic kidney disease, liver disorder, or blood disorders. Adults aged 60 to 74 who live in long-term care facilities or who are deemed frail would also qualify, as would people who are moderately or severely immunocompromised.

While a couple of members of the public raised concerns about the effect the new recommendation may have on vaccine uptake in people aged 60 to 74, committee members noted that the science on use of these products is evolving, and policy on their use will as well. ACIP member Matthew Daley noted after the votes that the panel perhaps should have added the words “at this time” to the wording of the votes, to make that point clear.