U.S. health regulators are reviewing deaths that may be linked to COVID-19 vaccines across several age groups as part of a broader safety reassessment, a spokesperson for the Department of Health and Human Services (HHS) said on Tuesday, according to Reuters.

HHS did not specify which age groups are included in the Food and Drug Administration’s (FDA) inquiry. FDA Commissioner Marty Makary had previously noted that the agency was examining such cases among younger people.

Last month, the agency’s chief medical and scientific advisor, Vinay Prasad, informed staff in a memo that COVID vaccine doses may have contributed to the deaths of at least 10 children who suffered heart inflammation. He also outlined plans to strengthen oversight of vaccines.

The memo did not detail any underlying conditions or identify the manufacturers involved. The findings—based on a preliminary review of 96 deaths recorded between 2021 and 2024—have not been published in a medical journal.

Moderna and Pfizer Respond
Moderna reiterated that there are no new or unpublished safety concerns regarding its mRNA-based vaccine for children or pregnant individuals.

Pfizer, which produces another mRNA COVID vaccine with BioNTech, also reaffirmed the shot’s safety and effectiveness.

Health Secretary Robert F. Kennedy Jr. has enacted sweeping changes to U.S. COVID vaccination policy, restricting access to those aged 65 and older as well as people with underlying health conditions.

Kennedy—long known for his criticism of vaccines—has driven broad shifts in federal immunization policy, including ending the longstanding recommendation for infant hepatitis B vaccination, reducing funding for mRNA vaccines, and promoting claims that vaccines are linked to autism, a view rejected by the scientific community.