In an unusual move, federal health officials have narrowed their recommendations for who should get vaccinated against the respiratory syncytial virus.
The Centers for Disease Control and Prevention recommended last year that adults 60 and older can get the RSV vaccine once in their lifetime, in consultation with their health care provider.
On Wednesday, the agency's scientific advisers updated their guidelines, unanimously recommending that all Americans 75 and older get one dose of the RSV vaccine, based on the latest safety and effectiveness data.
But for adults aged 60 to 74, the vaccine is only recommended for those with certain serious conditions, such as chronic heart or lung disease, advanced kidney disease or diabetes with organ damage.
The advisers voted not to recommend the vaccine for other adults in that age group, but individuals can speak to their health care provider to assess the risk that infection poses.
CDC Director Dr. Mandy Cohen endorsed the committee's recommendation Wednesday afternoon.
The US Food and Drug Administration has approved three RSV vaccines: two of them, GSK's Alexi and Pfizer's Avrisvo, were approved in May last year and administered in the fall and winter, while the third, an mRNA vaccine called mRESVIA from Moderna, was approved just this May.
Authorities said in February that the vaccine may have caused cases of Guillain-Barré syndrome, a rare neurological disorder. An analysis of the data presented to the committee on Wednesday revealed few concerns about the vaccine.
That uncertainty has fueled hesitancy among advisers as they weigh the vaccine's relative benefits and harms. GBS is “not a small consequence,” said Dr. Jamie Lohr, a family medicine practitioner in Ithaca, New York, and one of the advisers.
“Patients who contract the disease often spend three to four months in hospital, are intubated and can die,” he said.
Concerns about side effects played an especially large role in GSK's consideration of expanding eligibility for Alexi to adults between 50 and 59 years old. The FDA approved Alexi for use in that age group in June.
But at a meeting Wednesday, CDC advisers concluded that for most Americans in that age group, the risk of RSV infection is not high enough to justify the potential harms and costs of vaccination.
“We want to prevent even one person who is not at risk from contracting GBS from an unnecessary vaccine,” Dr. Camille Cotton, one of the advisers, said in an interview.
The panelists plan to continue to review their recommendations as more data becomes available, and at this point, Dr. Cotton said, “we don't want to rush into making recommendations for low-risk populations.”
Some committee members noted it's important to get the vaccine to adults when they are most at risk.
The vaccine is intended to be given as just one dose, as clinical trials showed that a second shot did not significantly boost immunity.
Some advisers say that if Americans who are not at high risk get vaccinated at a young age, their immunity to the virus may have waned by the time they really need protection.
As with other respiratory diseases, the risk of RSV infection increases sharply with age: Between 2016 and 2020, the virus caused up to 140,000 hospitalizations per year in Americans aged 65 and older, compared with fewer than 20,000 in those aged 60 to 64.
In hospitalized, unvaccinated adults, the severity of RSV infection is comparable to COVID-19 and influenza. Chronic illnesses further increase risk: Among adults 65 and older, those with heart failure are more than three times more likely to be hospitalized, according to data presented at the CDC meeting.
Several advisers worried that narrowing the number of Americans ages 60 to 74 eligible for RSV vaccination would send the “wrong message” about the vaccine's safety, but they ultimately all voted to approve the new criteria.