Day 1 Recap from CDC ACIP Meeting: COVID, Pneumococcal, Influenza, and RSV Vaccine Recommendations

The Advisory Committee on Immunization Practices (ACIP), composed of medical and public health experts, is tasked with creating vaccine recommendations for the civilian population in the United States. These guidelines provide essential public health advice for safely administering vaccines and related biological products.¹

COVID-19 Vaccine

Expected: The ACIP has put forth a draft vote recommending a second dose of the 2024-2025 COVID-19 vaccine for adults aged 65 and older, as well as for moderately or severely immunocompromised individuals aged 6 months to 64 years. Additionally, it suggests that individuals aged 6 months and older who are moderately or severely immunocompromised may require three or more doses under shared clinical decision-making. Specific guidance is also provided for those who are unvaccinated or have varying vaccination histories.²

Outcomes: The CDC vaccine advisory group has recommended a second COVID-19 vaccine dose for individuals aged 65 and older and younger individuals with moderate to severe immunocompromising conditions, spaced 6 months apart. They also suggested that immunocompromised individuals may need three or more doses based on shared decision-making with healthcare providers. This replaces the previous vague terminology used by ACIP.³

The unanimous vote addressed ongoing challenges with COVID-19, including unpredictable seasonal variations and waning vaccine effectiveness. Current data shows that only 40% of adults aged 65 and older received one vaccine dose, with just 8.9% getting a second dose. For immunocompromised individuals aged 18 and older, second-dose coverage is even lower at 5.4%. ACIP also recommended a minimum 2-month interval for additional doses in immunocompromised individuals aged 6 months and older.³

Pneumococcal Vaccine

Expected: In relation to pneumococcal vaccines, the draft vote recommends the pneumococcal conjugate vaccine (PCV) for all PCV-naive adults aged 50 years and older.²

Outcomes: ACIP discussed the potential recommendation for a single dose of pneumococcal conjugate vaccine for PCV-naïve adults aged 50–64 years. While most members supported the recommendation, about 25% expressed opposition. Economic analyses indicated a higher cost per quality-adjusted life year (QALY) gained for PCV20 compared to PCV21. The committee also noted uncertainties regarding the impact of pediatric PCV use and the duration of protection. Additionally, there were concerns about the broader implications of recommending a vaccine given the differences in serotype coverage between PCV20 and PCV21. Ultimately, ACIP proposed recommending the pneumococcal conjugate vaccine for all PCV-naïve adults aged 50 years and older.³

Influenza Vaccine

Expected: The draft Vaccines for Children (VFC) vote seeks to approve an updated resolution that includes high-dose and adjuvanted inactivated influenza vaccines as options for 18-year-old solid organ transplant recipients receiving immunosuppressive medications.²

Outcomes: A VFC resolution has been proposed to include vaccination options for 18-year-olds who are recipients of solid organ transplants.³

RSV: Consideration for Clesrovimab in Infants

The work group is evaluating whether clesrovimab should be recommended for all infants under 8 months entering their first RSV season or born during the RSV season. Preliminary evidence suggests that clesrovimab is highly effective, showing a 90.9% efficacy in preventing RSV-associated hospitalizations in a Phase 2b/3 trial.³

Safety data indicated that serious adverse events were balanced between the clesrovimab and placebo groups, although rare adverse events may not be detectable in such trials. Initial data appear promising, but the work group has requested further pharmacokinetic and safety information from the manufacturer.³

Clesrovimab has a shorter half-life compared to nirsevimab, but efficacy against severe RSV was sustained for at least 150 days. The work group is also considering additional evidence, including cost-effectiveness analysis and the Evidence to Recommendation Framework, with a summary anticipated by February 2025. The final ACIP vote will depend on FDA licensure.³

Watch Contagion's exclusive interview with Anushua Sinha, MD to learn more about Merck’s study on Clesrovimab in infants: https://www.contagionlive.com/view/merck-s-clesrovimab-shows-effectiveness-in-rsv-prevention-for-infants

References

1. Advisory Committee on Immunization Practices (ACIP). CDC. September 10, 2024. Accessed October 24, 2024. https://www.cdc.gov/acip/about/index.html

2. Next ACIP Meeting: Anticipated Votes. CDC. October 7, 2024. Accessed October 24, 2024.

3. ACIP Presentation Slides: October 23-24, 2024 Meeting. CDC. October 24, 2024. Accessed October 24, 2024. https://www.cdc.gov/acip/meetings/presentation-slides-october-23-24-2024.html