NIH Director Jay Bhattacharya will temporarily lead the Centers for Disease Control and Prevention until President Trump designates a permanent director. The CDC has lacked an acting leader since August 2025, when Health and Human Services Secretary Robert F. Kennedy Jr. terminated Susan Monarez’s tenure as its head. Deputy Health Secretary Jim O’Neill has served in that role since then.

Bhattacharya gained prominence during the pandemic for his vocal opposition to CDC measures. As a Stanford Medical School professor, he frequently criticized lockdowns and expressed deep skepticism about mask mandates, actively advocating for natural immunity through social media platforms. His recent actions include scaling back childhood vaccine recommendations—a move raising alarms among pediatricians and public health experts who fear diseases previously controlled by immunizations could resurge.

In testimony before Congress earlier this month, Bhattacharya urged vaccination against measles amid the nation’s largest outbreak in decades while denying any link between vaccines and autism. “I have not seen a study that suggests any single vaccine causes autism,” he stated during a Senate hearing.

Bhattacharya also co-authored the Great Barrington Declaration, a 2020 petition advocating for relaxed pandemic restrictions to allow natural immunity development while protecting vulnerable populations. The proposal faced widespread criticism as “unethical” from World Health Organization Director-General Dr. Tedros Adhanom Ghebreyesus and others in public health circles.

Throughout the pandemic, Bhattacharya maintained his stance against lockdowns, mask mandates, and vaccine passports before being appointed to lead the National Institutes of Health by HHS Secretary Robert F. Kennedy Jr.