The Department of Health and Human Services has hired an Army doctor with a history of questioning Covid vaccine safety to investigate unsubstantiated claims that more than 2,500 U.S. service members died after receiving the shots. The hiring of Lt. Col. Theresa Long, who has no specialized training in vaccines or viruses, is part of Health Secretary Robert F. Kennedy Jr.’s intense campaign to explore long-held and baseless theories about vaccine hazards. There is little evidence to support this latest investigation. More than 96 percent of service members were vaccinated before the mandate was rescinded. Pentagon reports in March and July 2025 found no deaths from the vaccines.

Dr. Long said in an Aug. 14 legal deposition that she is a senior medical military adviser to Mr. Kennedy but also reports to Defense Secretary Pete Hegseth. She said she was appointed to investigate 55,000 reports of adverse effects and 2,544 deaths among service members in the Vaccine Adverse Event Reporting System. Experts note this database is the least reliable, as reports are unvetted and can be biased.

Dr. Long also echoed inaccurate comments from Mr. Kennedy suggesting vaccines may cause autism and claiming pregnancy loss rates of 82 percent, contradicting studies of hundreds of thousands of women. The 2026 Pentagon report found Covid vaccines decreased incidence of eight conditions, including acute kidney failure and hemorrhagic stroke. Dr. Long called the report cherry-picked and hopes to complete her investigation within a year.

Experts like Dr. Ofer Levy of Boston Children’s Hospital support research into vaccine safety in young men, a high-risk group for myocarditis, but note proving exact causes of death is difficult.