A federal vaccine committee made recommendations Wednesday for a new pentavalent meningococcal vaccine and a chikungunya vaccine, both of which could be used in certain adolescents.
These recommendations from the Advisory Committee on Immunization Practices (ACIP) typically would need approval from the Centers for Disease Control and Prevention (CDC) director. A CDC spokesperson said the chief of staff "will take receipt" of the recommendations in the absence of a director.
During an all-day meeting, ACIP also discussed extending use of a meningococcal vaccine to infants and toddlers and a new monoclonal antibody to protect infants from respiratory syncytial virus (RSV) (Click links to jump to each section).
Meningococcal vaccine for adolescents and young adults
GSK’s pentavalent meningococcal vaccine (MenABCWY; Penmenvy) combines its Menveo MenACWY vaccine and its Bexsero MenB vaccine. It was licensed by the Food and Drug Administration (FDA) in February as a two-dose series for people ages 10-25 years.
ACIP voted 15-0 in favor of using the vaccine in the same way as the pentavalent meningococcal vaccine from Pfizer (Penbraya) — as an option for people who are recommended to receive both MenACWY and MenB vaccines at the same visit. This includes healthy people ages 16-23 years who choose to receive MenB vaccination after a discussion with their health care provider. It also includes individuals 10 years and older who are at increased risk of meningococcal disease due to health conditions (persistent complement deficiencies, complement inhibitor use or functional or anatomic asplenia) and are due for both vaccines.
Vaccines with a MenB component are not interchangeable, and subsequent MenB component vaccine doses must be from the same manufacturer.
ACIP members had several questions about the logistics around the new recommendations.
“I agree with this, but I am very concerned about having three meningitis vaccines in the fridge,” said ACIP Chair Helen Keipp Talbot, M.D. “… It is going to require a great deal of review to see how this program runs.”
Meningococcal disease can be serious, but it is rare and has dropped significantly since vaccines were introduced. However, cases have been rising for the last couple of years, and the 503 cases reported in 2024 were the highest since 2013, according to preliminary data from the CDC.
ACIP will continue to discuss broader changes to the adolescent meningococcal vaccine schedule.
Meningococcal vaccine for infants and toddlers
ACIP also discussed a second MenACWY vaccine option for infants and toddlers with certain risk factors who are recommended for vaccination.
Sanofi’s MenQuadfi is licensed for people 2 years and older but is awaiting FDA approval to be used down to 6 weeks of age. Sanofi’s Menactra was discontinued, leaving GSK’s Menveo as the only MenACWY vaccine licensed for children under 2 years.
Three clinical studies conducted among healthy children found the change in antibody titers was similar between MenQuadfi and comparator vaccines after the fourth dose, according to the CDC.
Safety data showed similar solicited local and systemic reactions. However, in one study, 19 children receiving MenQuadfi experienced a febrile or nonfebrile seizure compared to one in the group receiving a different MenACWY vaccine. While all were deemed unrelated to MenQuadfi, an ACIP work group still has questions about these adverse events as well as four deaths across two studies that also were deemed unrelated to the vaccine.
The work group also noted the studies were done in healthy infants and not those with risk factors for whom the vaccine would be recommended. However, it said the benefits of another vaccine may outweigh the risks.
If the FDA licenses MenQuadfi for infants and toddlers this spring, ACIP could vote on its use in June.
ACIP voted 14-0 with one abstention Wednesday in favor of a new chikungunya vaccine for certain adolescent and adult travelers.
Chikungunya is a mosquito-borne disease largely found in tropical and subtropical regions. From 2012-’24, just over 5,000 cases were reported in U.S. travelers. From 2022-’24, about 100-200 cases in U.S. travelers were reported each year, although that figure may be an undercount, according to the CDC.
The CDC estimates the risk of chikungunya for one week of travel to an outbreak area is 667 cases and 27 hospitalizations per 100,000 people.
Fever and joint pain are the most common symptoms in people with chikungunya. For some, the joint pain is severe and debilitating and can last for months.
The chikungunya virus-like particle vaccine (CHIK-VLP; Vimkunya) from Bavarian Nordic was licensed in the U.S. in February 2025 and indicated as a single dose for ages 12 years and older. It is the only chikungunya vaccine licensed for adolescents.
Randomized, controlled trials showed the vaccine likely provides good short-term protection, while rates of serious adverse events were similar to a placebo group. However, the vaccine was licensed through an accelerated approval pathway, and more studies will be conducted.
ACIP recommends CHIK-VLP for people ages 12 years and older traveling to a country or territory where there is a chikungunya outbreak. In addition, vaccination may be considered for people 12 years and older traveling or taking up residence in a country or territory without an outbreak but with elevated risk for U.S. travelers planning to travel for an extended period.
Pregnancy is a precaution for CHIK-VLP vaccination, while breastfeeding is not a contraindication or precaution. The CDC will publish detailed guidance for these populations.
ACIP continued to discuss a new immunization to protect infants from RSV.
Merck’s clesrovimab is a long-acting monoclonal antibody and is proposed for use in infants under 8 months of age born during or entering their first RSV season, similar to nirsevimab from Sanofi and AstraZeneca.
Clesrovimab is given as a single dose, and the dosage is the same regardless of weight. The product is awaiting FDA approval. Unlike nirsevimab, it would not be indicated for older infants and toddlers at risk of severe disease entering their second RSV season.
A phase 2b/3 randomized, placebo-controlled clinical trial found efficacy of 91% against hospitalization and 60% for medically attended RSV. The trial did not find safety concerns, although the CDC noted rare events likely would not be detected due to the sample size.
An ACIP work group said there would be benefits to having multiple products for infants in case RSV develops resistance to one. There also may be fewer supply issues and more competitive pricing, both of which were major concerns when nirsevimab was rolled out in the 2023-’24 season.
ACIP could vote on clesrovimab in June if the FDA has approved licensure by that time.
The committee also met Tuesday and discussed COVID-19, measles, mpox, HPV and Lyme disease.
