US President-elect Donald Trump has named leading Covid lockdown skeptic Jay Bhattacharya as the next director of a key US health agency.

Trump said he had chosen the Stanford University-educated doctor and economist to lead the National Institutes of Health (NIH), the world’s largest federally funded biomedical research institution.

Bhattacharya became the face of a highly controversial open letter during the pandemic – known as the Great Barrington Declaration – that spoke out against widespread lockdowns.

Tuesday’s nomination rounds out Trump’s top public health team. He has already announced all 15 positions in his cabinet as he prepares to take office on January 20.

Earlier this month, Trump announced he would nominate his former rival Robert Kennedy Jr. to head the U.S. Department of Health and Human Services. Kennedy’s vaccine skepticism has alarmed the medical community, although his calls for stricter regulation of food ingredients received praise.

In a statement, Trump said Bhattacharya would work with Kennedy to “return the NIH to a gold standard of medical research as it investigates the underlying causes and solutions to America’s greatest health challenges, including our chronic disease crisis.”

On Tuesday, the president-elect also named Jim O’Neill — a former federal health official and close ally of conservative donor Peter Thiel — as deputy secretary of the Department of Health and Human Services.

Better known, however, is Bhattacharya, who questioned the public health response to the Covid outbreak four years ago.

In October 2020, Bhattacharya co-authored an open letter called the “Great Barrington Declaration” in which he called for an alternative to lockdowns and recommended that the focus should instead be on protecting vulnerable groups such as the elderly.

He remains a vocal critic of the handling of the pandemic by Anthony Fauci – a former director of the US National Institute of Allergy and Infectious Diseases, a division of the NIH.

Then-NIH Director Francis Collins said at the time that the Great Barrington Declaration, made before Covid vaccines were available, was dangerous and dismissed the authors as “fringe experts.”

Bhattacharya is not the only Trump candidate who has criticized U.S. health officials’ response to the pandemic.

Trump also appointed Marty Makary, a Johns Hopkins University surgeon who opposed Covid-19 vaccination requirements, to head the Food and Drug Administration (FDA).

Dave Weldon, a doctor and former Republican congressman who has also expressed doubts about the safety of vaccines, has been named head of the Centers for Disease Control and Prevention (CDC).

The Kennedy-O’Neill Department of Health would oversee all agencies run by Makary, Weldon and Bhattacharya, but they all must be confirmed by the Senate.

Last week, Trump also nominated TV personality Dr. Mehmet Oz as Administrator of the Centers for Medicare and Medicaid Services.

While Trump’s picks for U.S. health officials were widely welcomed by his allies, not all of them were well received by conservatives.

He also has Dr. Janette Nesheiwat, a Fox News medical contributor, nominated to be the next surgeon general.

Her previous comments opposing abortion restrictions and advocating for masking school children during the pandemic have angered some Trump supporters.