Advisory Committee Votes Bring Good News on Mpox, RSV Vaccines

While this was the only vote taken during the ACIP’s Feb. 22-24 meeting, the committee also discussed COVID-19 booster vaccines for certain patient populations and received updates on vaccines for several other infectious diseases.

Jynneos and Mpox

Jynneos, a replication-deficient orthopoxvirus vaccine, is administered in a two-dose series given 28 days apart. The vaccine received FDA approval in September 2019 for adults at increased risk of smallpox or mpox infection. In November 2021, the ACIP voted unanimously to recommend Jynneos as an alternative to the ACAM2000 vaccine for those at risk of mpox infection from potential occupational exposure.

The Biden administration declared mpox a public health emergency in August 2022 and ended the PHE on Jan. 31. At its peak, the United States had more than 450 confirmed mpox cases each day; the latest CDC data indicates an average of two new cases per day.

Nearly 1.2 million doses of Jynneos were administered during the outbreak.

COVID-19 Vaccines

Although no votes on COVID-19 vaccines were taken at the meeting, ACIP members had a lively discussion about the frequency of COVID-19 booster shots for older adults and those who are immunocompromised.

Currently, the CDC recommends that older individuals and people with moderate or severely weakened immune systems receive COVID-19 booster shots more frequently than people with strong immune systems. Officials with the ACIP’s COVID-19 Vaccines Work Group, however, found insufficient evidence to recommend more than one COVID-19 booster a year for these populations, and supported a plan for administering annual boosters, most likely in the fall.

The FDA in January tasked its Vaccines and Related Biological Products Advisory Committee with developing a strategy to “harmonize” the way COVID-19 vaccines and boosters are administered, and to simplify the composition of future vaccines. Any recommendations VRBPAC makes must be ratified by the FDA commissioner, then approved by the ACIP and the director of the CDC before going into effect.

Other Items of Note

The ACIP also reviewed updates on influenza activity; the epidemiology of pediatric pneumococcal disease, meningococcal disease and chikungunya; and recommendations on adult polio vaccination.

In addition, ACIP reviewed presentations on several potential treatment options for respiratory syncytial virus, including Nirsevimab, a single-dose, long-acting antibody designed to protect infants, and a pair of vaccines manufactured by Pfizer Inc. and GSK  to protect older adults. The vaccines were also discussed at a subsequent VRBPAC meeting.

RSV Vaccines Narrowly Approved

VRBPAC members voted 7-4 at their Feb. 28-March 1 meeting to recommend approving Abrysvo, a vaccine manufactured by Pfizer Inc., for active immunization to prevent acute respiratory disease and lower respiratory tract disease caused by RSV in adults 60 and older.

The committee also voted to recommend approval for Arexvy, a recombinant adjuvanted vaccine manufactured by GSK, for active immunization to prevent lower respiratory tract disease caused by RSV subtypes RSV-A and RSV-B subtypes in adults 60 and older.

If the FDA accepts the committee’s recommendations, Abrysvo and Arexvy would the first RSV vaccines approved for use in the United States. A decision from the FDA commissioner is expected in the coming weeks.