Should RSV Vaccination Expand to Younger High-Risk Groups?

Although the FDA has expanded approvals for two respiratory syncytial virus (RSV) vaccines to include high-risk young and middle-age adults, CDC advisors have not yet moved to recommend the vaccine in these groups.

In June, the FDA expanded the approval of GSK’s RSV vaccine (Arexvy) for use in adults ages 50 to 59 at risk of RSV-related lower respiratory tract disease due to underlying conditions, and in October, Pfizer’s bivalent prefusion F RSV vaccine (Abrysvo) was also granted an expanded approval to include the prevention of lower respiratory tract disease caused by RSV in high-risk adults ages 18 to 59.

All three RSV vaccines — including Moderna’s mRESVIA — were previously FDA-approved for all adults ages 60 and up, and Pfizer’s vaccine is also approved for use in pregnant women to protect infants.

However, the CDC’s Advisory Committee on Immunization Practices (ACIP) said in June that “insufficient evidence was available to inform an RSV vaccine recommendation” in adults ages 50-59 at increased risk. Currently, the CDC recommends a single dose of any FDA-approved RSV vaccine for all adults ages 75 and older, those ages 60 to 74 who are at increased risk of severe illness from the virus, and pregnant women.

So, how are physicians thinking about vaccination in young and middle-age adults who may be at risk from RSV?

“It is really a discussion of their individual health conditions that might place them at increased risk,” Albert Shaw, MD, PhD, of the Yale School of Medicine in New Haven, Connecticut, told MedPage Today.

“It is notable that now at least the Pfizer vaccine is approved for adults 18 [and up], and the question is, how do you think about who would benefit the most,” he said.

Though an 18- or 20-year-old is not necessarily comparable to a 60- or 70-year-old, this is something that clinicians will need to think about, including the chronicity of certain conditions, such as cardiac illness or lung disease, noted Shaw, who is also a voting member of ACIP, but was not speaking on behalf of the committee.

Data that show RSV is associated with risk for cardiac events, exacerbation of heart failure, and chronic obstructive pulmonary disease (COPD) flares can help “guide clinicians to navigating the approval” of the vaccine in younger adults, he said.

“If it is approved, they can give it,” he added. “That is no question.”

“There does seem to be some risk for GBS [Guillain-Barré syndrome], though rare,” in post-marketing data, Shaw noted, but it is better to have a vaccine and take this into consideration than to not have one.

Angela Branche, MD, of the University of Rochester Medical Center in New York, agreed that “being able to make recommendations about the RSV vaccines is really driven by the licensure.”

The scientific community understands that, even in younger and middle-age adults, if they are immunocompromised and become infected with RSV, “it could be a very serious illness for [them] as well,” she noted.

Meanwhile, the ongoing collection of real-world data will continue to be helpful, experts told MedPage Today.

“It is really critical to [be] sure that the vaccines do what they hope they will do,” Branche said.

So far, that seems to be the case.

“When we look specifically at the adults who are at most risk — those 75 years and older and those with severe underlying medical conditions — going into it, we had really hoped the vaccine would perform well in those groups, knowing that they are at highest risk,” said Amanda Payne, PhD, of the CDC. “So it was really comforting to see that it did indeed provide protection in those groups.”

“That gave us confidence that, again, the vaccine in a real-world setting is doing what we hoped it would do,” she added.

Shaw noted that “we want to be guided by data,” and real-world data are “really valuable for looking at a broader range of the population,” including individuals who are immunocompromised.

Indeed, one of the populations to think about going forward are patients who have had a lung transplant or bone marrow transplant, or those with leukemia, who may be at highest risk of severe illness from RSV, he said.

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