CDC Panel Backs Broader Use of Mpox Vaccine

The CDC’s vaccine advisors on Wednesday endorsed the use of the mpox vaccine for high-risk adults even after the outbreak, along with a newly approved pentavalent meningococcal vaccine for adolescents and younger adults.

Broader Mpox Vaccine Use

By a 14-0 vote, the Advisory Committee on Immunization Practices (ACIP) recommended the two-dose Jynneos vaccine for mpox prevention in adults at risk for infection, which typically passes through close skin-to-skin contact, including sex.

The move will expand use of the replication-deficient vaccinia virus beyond outbreaks, as determined by public health authorities, though the new guidance will be revisited in the next 2 to 3 years.

A routine recommendation could potentially “increase vaccine coverage and prevent or minimize future outbreaks and control the current outbreak,” explained Pablo Sanchez, MD, chair of the ACIP Mpox Work Group.

It would also remove some stigma and facilitate one-to-one consultation with clinicians during individuals’ appointments for vaccination, added Sanchez.

Since the outbreak began in 2022, there have been more than 30,000 mpox cases reported and at least 54 deaths associated with the virus in the U.S., according to the CDC. The current average is about one new case per day.

Groups considered at-risk for mpox include men who have sex with men (MSM) and transgender or nonbinary people who in the past 6 months have had a new diagnosis of a sexually transmitted disease, multiple sex partners, engaged in sex work, or who had sex in association with a large public event in a region where mpox is circulating. Also people who anticipate exposure to those risks and the partners of these individuals.

Vaccine effectiveness estimates with the recommended two-dose Jynneos vaccine (given 28 days apart) range from 66% to 89%. The vaccine is currently approved for both smallpox and mpox.

Given the rarity of infection among healthcare personnel (mostly via sharp injuries), vaccination is not routinely recommended for clinicians unless sexual risk factors are present, a CDC medical officer said.

With the broader recommendation for routine use in at-risk adults, it’s expected that vaccine-maker Bavarian Nordic will introduce Jynneos to the commercial sector, transitioning its availability from federal government stockpiles (originally intended for smallpox preparedness).

An NIH trial to determine the vaccine’s safety and immunogenicity for individuals ages 12 to 17 is ongoing, and ACIP is expected to consider the results in 2024.

Meningitis Recommendations

The committee also voted 10-4 in favor of recommending the newly approved pentavalent meningococcal vaccine (Penbraya) when both the MenACWY and bivalent MenB vaccines are indicated at the same visit. It’s the first vaccine to provide protection against the five meningococcal serogroups (A, B, C, W, and Y; MenABCWY) responsible for most cases of invasive meningococcal diseases globally.

Currently, children receive their first dose of MenACWY at ages 11 to 12 years followed by a booster dose at age 16. And individuals ages 16 to 23 receive two doses of MenB using shared clinical decision-making.

Reactogenicity to the serogroup B component of the new vaccine was a concern for some panelists, particularly in light of the low burden of serogroup B meningococcal disease in younger adolescents and those not attending college.

But other ACIP members who voted “no” also voiced support for a broader recommendation for the new vaccine.

The pentavalent vaccine gained approval earlier this month for individuals ages 10 to 25 years, based on phase III trial data in previously unvaccinated individuals that showed noninferior immune responses and comparable safety with MenABCWY when compared with vaccination with the MenACWY (Menveo) and MenB (Trumenba) vaccines.

While meningitis is rare in the U.S., mortality is 10% to 15%. Most cases occur among children younger than 1 year, adolescents and young adults ages 16 to 23, and adults older than 85.

The meningococcal vaccine work group plans to revisit the adolescent schedule for meningococcal vaccines over the next 15 months.

ACIP on Wednesday also voted unanimously to include both the mpox and new meningococcal vaccines in the Vaccines for Children Program, a federally funded program that provides vaccines at no cost to children in need.