This transcript has been edited for clarity.
ACIP, the CDC’s Advisory Committee on Immunization Practices, met for 3 days in June. New vaccines and new recommendations for respiratory syncytial virus (RSV), flu, COVID, and a new pneumococcal vaccine were revealed.
RSV Protection
We’ll begin with RSV vaccines for adults aged 60 or older. For this group, shared clinical decision-making is out; it no longer applies. New, more specific recommendations from ACIP for RSV vaccines are both age based and risk based. The age-based recommendation applies to those aged 75 or older, who should receive a single RSV vaccine dose. If they have already received a dose under the old recommendation, they don’t need another one, at least for now.
The risk-based recommendation applies to adults from age 60 up to 75, but only for those with risk factors for severe RSV. These risk factors include lung disease, heart disease, immunocompromise, diabetes, obesity with a BMI of 40 or more, neurologic conditions, neuromuscular conditions, chronic kidney disease, liver disorders, hematologic disorders, frailty, and living in a nursing home or other long-term care facility. Those aged 60-75 with these risk factors should receive the RSV vaccine, and those without them should not receive it. The best time to get the RSV vaccine is late summer, but early fall administration with other adult vaccines is allowed and is acceptable.
Vaccine safety concerns were top of mind as ACIP members began their deliberations. Possible safety concerns for RSV vaccines have been detected for Guillain-Barré syndrome, atrial fibrillation, and idiopathic thrombocytopenic purpura. Safety surveillance updates are still interim and inconclusive. These signals still need further study and clarification.
Two RSV vaccines have been on the market: one by Pfizer, called Abrysvo, which does not contain an adjuvant; and another one by GSK, called Arexvy, which does contain an adjuvant. With the recent FDA approval of Moderna’s new mRNA RSV vaccine, mRESVIA, there are now three RSV vaccines licensed for those 60 or older. Arexvy is now FDA approved for adults in their 50s. That just happened in early June, but ACIP doesn’t currently recommend it for this fifty-something age group, even for those at high risk for severe RSV disease. This may change with greater clarification of potential vaccine safety concerns.
There is also news about protecting babies from RSV. RSV is the most common cause of hospitalization for infants in the United States, and most hospitalizations for RSV are in healthy, full-term infants. We now have two ways to protect babies: a dose of RSV vaccine given to mom, or a dose of the long-acting monoclonal antibody nirsevimab given to the baby. ACIP clarified that those who received a dose of maternal RSV vaccine during a previous pregnancy are not recommended to receive additional doses during future pregnancies, but infants born to those who were vaccinated for RSV during a prior pregnancy can receive nirsevimab, which is recommended for infants up to 8 months of age during their first RSV season, and for high-risk infants and toddlers aged 8-19 months during their second RSV season.
Last RSV season, supplies of nirsevimab were limited and doses had to be prioritized. No supply problems are anticipated for the upcoming season. A study published in March showed that nirsevimab was 90% effective at preventing RSV-associated hospitalization for infants in their first RSV season.