How emergency authorities, executive action, and temporary federal mechanisms can change vaccine policy during public health crises
Under normal conditions, vaccine policy follows a standard route: scientific research leads to FDA review, then ACIP recommendation, CDC policy adoption, coverage and program effects, and eventually state and institutional decisions. That process is explained on the U.S. Federal Vaccine Policy and State School Vaccination Requirements pages.
During declared public health emergencies, the federal government can also use additional authorities that operate alongside — and sometimes independently of — that standard path. These emergency authorities can affect how quickly products become available, who bears legal liability, how injuries are compensated, and what conditions are placed on federal employees, contractors, healthcare facilities, and international travelers.
Emergency authorities do not replace the standard vaccine policy system. They add temporary mechanisms that can change the speed, legal framework, and operational tools of vaccine policy for the duration of an emergency or until they are revoked, withdrawn, or blocked by courts.
The federal government has several legal tools available during declared public health emergencies. Each has a specific statutory basis, scope, and set of limitations.
Under Section 564 of the Federal Food, Drug, and Cosmetic Act, the FDA can authorize the use of unapproved medical products — or unapproved uses of approved products — to diagnose, treat, or prevent serious or life-threatening diseases during a declared emergency. An EUA is not the same as full FDA approval. It requires a lower evidentiary threshold but is subject to specific conditions and can be revised or revoked as circumstances change.
During the COVID-19 pandemic, EUAs allowed vaccines to become available before completing the standard full-approval process. Several COVID-19 vaccines later received full FDA licensure through the standard Biologics License Application (BLA) pathway.
The Public Readiness and Emergency Preparedness Act (42 U.S.C. section 247d-6d) provides liability immunity to manufacturers, distributors, healthcare providers, and program planners for covered countermeasures when the HHS Secretary issues a declaration. This immunity applies except in cases of willful misconduct.
PREP Act protections are not permanent. They are tied to specific emergency declarations and apply only to the countermeasures and time periods defined in those declarations. They do not apply to routine vaccines on the standard childhood schedule unless a specific declaration covers them.
For more detail on the PREP Act, see the PREP Act and Liability page.
When a PREP Act declaration is in effect, injuries resulting from covered countermeasures are handled through the Countermeasures Injury Compensation Program (CICP), administered by HRSA — not through the standard National Vaccine Injury Compensation Program (VICP).
The CICP differs from the VICP in several important ways: it has a shorter filing window (generally one year from the date of administration), a different standard of proof, no judicial review process, and more limited compensation categories. This distinction matters because individuals injured by emergency-authorized vaccines may face a more restrictive compensation pathway than those injured by routinely recommended vaccines.
For more detail on the VICP and vaccine injury compensation, see the VICP Program and Vaccine Court pages.
Federal agencies can set health and safety standards as conditions for participating in federal programs. During the COVID-19 pandemic, the Centers for Medicare and Medicaid Services (CMS) used this authority to require vaccination for staff at facilities receiving Medicare and Medicaid funding. This mechanism tied vaccination status to a facility's eligibility for federal healthcare reimbursement.
The use of emergency authorities during 2021 and 2022 led to two significant Supreme Court decisions that defined the boundaries of federal power in this area. Understanding why one was upheld and the other was blocked helps explain how courts evaluate emergency-era vaccine policy.
The Supreme Court allowed the CMS vaccination requirement for healthcare workers at Medicare- and Medicaid-certified facilities to take effect. The majority ruled that the Secretary of HHS had clear statutory authority to ensure that healthcare providers receiving federal funds maintain infection control and patient safety standards. Because CMS had long regulated health and safety conditions at participating facilities, the Court found the vaccination requirement was within the scope of that existing authority.
The Supreme Court stayed OSHA's Emergency Temporary Standard (ETS), which would have required vaccination or weekly testing for employees at businesses with 100 or more workers. The Court ruled that while OSHA has authority to regulate occupational hazards specific to the workplace, COVID-19 was a universal public health risk — not a distinctly occupational one. The majority concluded that a mandate of this scope and significance required clear congressional authorization, not agency action under existing workplace-safety law.
OSHA later withdrew the ETS as an enforceable emergency standard while leaving it as a proposed rule that was never finalized.
These two cases illustrate an emerging judicial framework known as the Major Questions Doctrine. Under this doctrine, federal agencies cannot claim broad regulatory authority on questions of vast economic and political significance unless Congress has clearly authorized that specific power. The CMS rule survived because the Court found clear statutory authority in the existing Medicare/Medicaid framework. The OSHA rule did not survive because the Court found no comparably clear congressional authorization for a sweeping employer vaccination mandate.
Between 2021 and 2023, the executive branch implemented vaccination requirements for specific categories of the federal workforce. These were separate from the CMS and OSHA rules and operated under different legal authorities.
Executive Order 14042, issued September 9, 2021, required certain federal contractors and subcontractors to ensure their employees were vaccinated against COVID-19. The order used the Federal Property and Administrative Services Act (FPASA) as its legal basis, framing vaccination as a measure to promote economy and efficiency in federal procurement. The requirement was the subject of significant litigation and was largely enjoined by various federal courts before being formally revoked.
Executive Order 14043, also issued September 9, 2021, required vaccination for federal civilian employees, with limited exceptions for medical and religious accommodations.
Both Executive Order 14042 and Executive Order 14043 were formally revoked by Executive Order 14099, issued May 9, 2023 and effective May 12, 2023. The revocation coincided with the end of the federal COVID-19 Public Health Emergency. Federal agencies were directed to cease enforcing policies premised on the revoked orders.
The Department of Defense mandated COVID-19 vaccination for all service members in August 2021. This mandate was rescinded on January 10, 2023, following a requirement in the FY2023 National Defense Authorization Act (NDAA). A subsequent executive order in January 2025 addressed the reinstatement of service members who had been discharged for refusing vaccination.
During the COVID-19 pandemic, federal agencies implemented vaccination requirements for certain categories of international travelers entering the United States.
Federal agencies relied on public health authorities under the Public Health Service Act (42 U.S.C. section 264) and related entry-control authorities to implement these requirements.
Under this authority, the CDC and the Department of Homeland Security required proof of COVID-19 vaccination for non-citizen, non-immigrant air travelers and certain land-border travelers entering the United States. Airlines and other carriers were responsible for verifying vaccination status prior to boarding.
These travel vaccination requirements ended on May 12, 2023, coinciding with the expiration of the federal COVID-19 Public Health Emergency. As of April 2026, federal health agencies issue travel health recommendations but do not enforce vaccination as a condition of entry into the United States.
Emergency authorities changed specific aspects of vaccine policy during the pandemic period, but they did not fundamentally restructure the U.S. vaccine governance system.
The federal government did not acquire general authority to mandate vaccination for the public at large. The police power — the authority to protect public health and safety through requirements, penalties, and enforcement — remains with the states under the 10th Amendment. Emergency-era federal actions were targeted at specific populations or settings (healthcare facilities, federal employees, contractors, international travelers), not at the general public.
Most emergency-era vaccination requirements were tied to specific emergency declarations, executive orders, or agency rules that have since expired, been revoked, or been withdrawn. The end of the federal COVID-19 Public Health Emergency on May 11, 2023 marked the formal expiration of many of these authorities.
Liability protections under the PREP Act applied only for the duration and scope of the relevant emergency declaration. They did not permanently alter the liability framework for routine vaccines, which continues to operate through the VICP and standard product-liability law.
Throughout the emergency period, the standard vaccine policy system — ACIP recommendations, CDC scheduling, state school-entry requirements, and institutional policies — continued to function. Emergency mechanisms operated alongside this system, not as a replacement for it.
As of April 2026, the primary federal mandates — for contractors (EO 14042), civilian employees (EO 14043), and military service members — have all been revoked or rescinded. Some healthcare facilities may still maintain vaccination policies as part of CMS-compliant infection control programs, but these are facility-level decisions within existing regulatory frameworks.
The federal OSHA mandate was blocked and later withdrawn, but private employers generally retain the right to set conditions of employment under applicable state law. Employer vaccination policies must comply with federal civil rights protections, including reasonable accommodations under the Americans with Disabilities Act (ADA) and Title VII religious accommodations.
Claims for injuries from COVID-19 vaccines administered under a PREP Act declaration are filed with the Countermeasures Injury Compensation Program (CICP), not the standard VICP. The CICP filing deadline is generally one year from the date of vaccine administration. For more information, see the HRSA CICP page.
An Emergency Use Authorization allows a product to be used during a declared emergency based on available evidence that the product may be effective and that the known and potential benefits outweigh the known and potential risks. Full FDA approval (via a Biologics License Application) requires a more comprehensive review of safety, efficacy, and manufacturing data. Several COVID-19 vaccines initially authorized under EUA later received full FDA approval.
No. Emergency-era federal policies operated through different legal authorities and affected different populations than state school-entry requirements. State school vaccination requirements continued to be governed by state law throughout the pandemic period.