Changes Announced in Immunization Recommendations by Health Secretary

Background of the Policy Change

On May 27, 2025, Health and Human Services Secretary Robert F. Kennedy Jr. announced via social media that the Department of Health and Human Services had unilaterally removed the seasonal COVID-19 booster from the CDC’s Recommended Immunization Schedule for healthy children and pregnant people. This move bypasses the traditional Advisory Committee on Immunization Practices (ACIP) process, which typically involves public meetings, peer review, and expert voting.

Joining Kennedy in the announcement were FDA Commissioner Martin Makary and NIH director Jay Bhattacharya. Kennedy claimed a “lack of any clinical data” to support boosters in these groups despite multiple peer-reviewed studies. The decision follows last week’s FDA framework restricting COVID-19 boosters to adults 65+ and those with high-risk conditions, which still explicitly listed pregnancy as a qualifying risk factor.

Evidence for Booster Effectiveness in Vulnerable Populations

Contrary to the Secretary’s claims, several datasets and clinical trials show robust booster benefits:

• CDC Real-World Effectiveness (2023–2024): In a presentation led by epidemiologist Ruth Link-Gelles at CDC, data demonstrated 52% added protection against urgent/emergency care visits in children aged 9 months to 4 years, and 64% in ages 5–17, over existing immunity.
• Immunogenicity Metrics: Booster doses of bivalent mRNA vaccines raise geometric mean titers (GMT) of neutralizing antibodies (e.g., VNT₅₀ titers) by 5–10× within 14 days post-dose. T-cell analyses show a 2–3× increase in SARS-CoV-2 spike–specific CD4⁺ and CD8⁺ responses.
• Pregnancy & Neonatal Protection: A New England Journal of Medicine study (2022) reported a 61% reduction in hospitalization for infants <6 months when mothers received at least one mRNA vaccine dose during pregnancy.

Regulatory and Legal Implications

The sudden policy shift raises questions under the Federal Advisory Committee Act (FACA) and the Public Health Service Act. ACIP meetings occur publicly with stakeholder input from manufacturers (Pfizer, Moderna), clinicians, and patient groups. Skipping this process may:

1. Violate Section 564 (Emergency Use Authorization) procedural safeguards.
2. Trigger legal challenges from state health departments asserting preemption arguments over vaccine mandates.
3. Undermine trust in the CDC’s independent review model, which has guided over 70 vaccine recommendations since 1995.

Public Health Impact and Modeling Predictions

Mathematical models from the Institute for Health Metrics and Evaluation (IHME) and CDC’s Modeling Task Force project that removing boosters could increase:

• Hospitalizations in children aged 5–11 by up to 20% during a fall‐winter surge, based on SIR compartmental modeling including waning immunity parameters.
• ICU admissions among pregnant people by 15–18%, accounting for higher rates of preeclampsia and thromboembolic events with severe COVID-19.

Global and Variant Context

While the U.S. pivots, the WHO’s Strategic Advisory Group of Experts (SAGE) on Immunization continues to recommend boosters for high-risk groups, including pregnant individuals. Recent variant surveillance shows emerging strains (XBB.1.5, BA.2.86) with up to a 4-fold reduction in neutralization by sera from primary-series recipients—reinforcing the need for updated bivalent boosters.

Expert Opinions and Stakeholder Reactions

“Removing these recommendations without transparent data review risks significant public health harm,” said Dr. Rochelle Walensky, former CDC Director. “We have ample immunogenicity and efficacy evidence supporting boosters in children and pregnant people.”

The American College of Obstetricians and Gynecologists (ACOG) and the American Academy of Pediatrics issued statements reaffirming that vaccination remains the safest way to protect mothers and infants. Industry leaders from Pfizer and Moderna also warned that vaccine uptake could decline, undermining progress against COVID-19.

Next Steps and Outlook

The CDC Advisory Committee on Immunization Practices will convene June 25–27. Topics will include:

• Review of new Phase 3 pediatric trial data on bivalent boosters.
• Discussion of updated maternal immunization schedules.
• Potential reinstatement motions to restore recommendations.

State health agencies and pediatric societies are closely monitoring developments. Many anticipate legal appeals or state‐level mandates if federal guidance remains withdrawn. Clinicians nationwide face uncertainty in counseling families during a critical vaccination window.

Key Takeaways

1. The policy change is unprecedented, circumventing ACIP’s evidence‐based process.
2. Independent data strongly support booster efficacy and safety in children and pregnant individuals.
3. Public health models predict increased hospitalizations and adverse outcomes without boosters.