The Food and Drug Administration blocked the publication of several studies that found COVID-19 and shingles vaccines to be safe, according to a Department of Health and Human Services spokesperson.

The studies were conducted by FDA scientists and data contractors who analyzed millions of patient records to examine vaccine safety. The research found that serious side effects from both COVID-19 and shingles vaccines were rare, the HHS spokesperson confirmed to news outlets.

The blocked studies included research examining the safety of COVID-19 vaccines conducted in 2023 and 2024. The research was funded by taxpayer money and cost several million dollars to complete.

FDA scientists and their data contractors had reviewed the extensive patient record data before the studies were pulled back prior to release. The agency has not publicly explained its decision to block publication of the safety findings.

The blocked research represents a significant investment of public funds in vaccine safety monitoring, with the studies designed to provide transparency about potential side effects from widely administered vaccines.