WASHINGTON, D.C.: U.S. health officials have launched a broader investigation into deaths that may be linked to COVID-19 vaccines, extending the review across multiple age groups as federal regulators reassess vaccine safety and oversight, a Department of Health and Human Services (HHS) spokesperson said.

HHS did not specify which age categories are now being examined. The review builds on earlier remarks from U.S. Food and Drug Administration Commissioner Marty Makary, who said the agency had been evaluating deaths among young people.

The expanded scrutiny follows a memo last month from FDA chief medical and scientific officer Vinay Prasad, who told staff that COVID vaccinations had "probably contributed" to the deaths of at least 10 children who died of heart inflammation. He also announced plans to strengthen oversight of the shots.

The memo, based on an initial analysis of 96 deaths between 2021 and 2024, did not detail the children's medical histories or identify the manufacturers involved, and the findings have not been published in a peer-reviewed journal.

Moderna reiterated that it had identified "no new or undisclosed safety concerns" related to its mRNA shot, Spikevax, in children or pregnant women. Pfizer, which sells an mRNA-based COVID vaccine with BioNTech, also reaffirmed the product's safety and efficacy.

The review comes amid sweeping changes to federal vaccine policy under Health Secretary Robert F. Kennedy Jr., who has restricted access to COVID shots to people 65 and older and those with underlying conditions.

Kennedy, a longtime vaccine skeptic, has also overseen the rollback of a long-standing recommendation for the hepatitis B birth dose, reduced funding for mRNA vaccine research, and advanced claims, contrary to established scientific consensus, that link vaccines to autism.