Under former Health Secretary Robert F. Kennedy Jr., CDC scientists have been prevented from publishing a study showing significant health benefits of this season’s COVID-19 vaccines, according to The Washington Post.

The suppressed research revealed that healthy adults vaccinated against the virus saw their risk of emergency room visits and hospitalizations fall by 50% and 55%, respectively. However, acting CDC director Jay Bhattacharya withheld the report due to concerns over its methodology, despite it passing through rigorous scientific review.

Agency insiders told The Washington Post that fears of political backlash from the Trump administration prompted scientists to speak on condition of anonymity. This move has raised significant concern among health experts who worry about ongoing interference in federal science by anti-vaccine activists.