UPDATE: ACIP Vote Unanimous to Recommend Merck 21-Valent Pneumococcal Shot for Older Adults

Capvaxive (pneumococcal 21-valent conjugate vaccine) received a unanimous recommendation from the Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention as an "option for adults 65 years of age and older for pneumococcal vaccination."

Specifically ACIP recommends a single dose of Capvaxive for:

• All adults 65 years of age and older who have not previously received a pneumococcal conjugate vaccine or whose previous vaccination history is unknown;
• Adults 19-64 years of age with certain underlying medical conditions or other risk factors who have not previously received a pneumococcal conjugate vaccine or whose previous vaccination history is unknown;
• Adults 19 years of age and older who have started their pneumococcal vaccine series with PCV13 (pneumococcal 13-valent conjugate vaccine) but have not received all recommended PPSV23 (pneumococcal 23-valent polysaccharide vaccine) doses.

The committee also recommended that clinicians engage in shared decision making about use of a supplemental dose of the vaccine for adults aged 65 years and older who have completed a vaccine series with both PCV13 and PPSV23.

According to Merck, Capvaxive was formulated specifically for adults aged 50 years and older and designed to cover serotypes responsible for approximately 84% of invasive pneumococcal disease (IPD) in this population.²

The novel vaccine includes 8 unique serotypes that are not covered by currently FDA-approved pneumococcal vaccines, according to Merck. The 8 serotypes (15A, 15C, 16F, 23A, 23B, 24F, 31 and 35B) were responsible for approximately 27% of IPD cases in adult aged 50 years and older and approximately 31% in those aged 65 and older, according to 2018-2021 epidemiologic data data from the CDC.²

"Even with the availability of current pneumococcal conjugate vaccines for adults, gaps in serotype coverage for invasive pneumococcal disease persist,” Eliav Barr, MD, senior vice president, head of global clinical development and chief medical officer, Merck Research Laboratories said in a previous Merck statement.²

An adult-specific pneumococcal vaccine has been elusive since the first marketed formulation against the infection in 1977 (polysaccharide), followed by the first conjugate vaccine in 2000. Both significantly reduced disease in both children and adults. Subsequent conjugate formulations with additional serotypes were increasingly more effective in children, but not in adults.

Among the clinical data supporting the approval are results from the pivotal phase 3 STRIDE-3 trial (NCT05425732), which evaluated Capvaxive compared to PCV20 in adults 18 years of age and older who had not previously received a pneumococcal vaccine. The approval is also supported by results from the phase 3 STRIDE-5 (NCT05526716) and STRIDE-6 (NCT05420961) trials evaluating Capvaxive in vaccine-naïve and vaccine-experienced adults.

These provisional recommendations will be official once reviewed and finalized by the director of the CDC and the Department of Health and Human Services.

References
1. CDC's ACIP unanimously recommends Merck's Capvaxive (pneumococcal 21-valent conjugate vaccine) for pneumococcal vaccination in appropriate adults. News release. Merck. June 27, 2024. Accessed July 1, 2024. https://www.merck.com/news/cdcs-acip-unanimously-recommends-mercks-capvaxive-pneumococcal-21-valent-conjugate-vaccine-for-pneumococcal-vaccination-in-appropriate-adults/
2. Halsey G. FDA approved Merck's 21-valent pneumococcal vaccine for adults 50 years of age and older: a first and long-awaited. Patient Care Online. June 18, 2024.