By Michael R. Bloomberg

One of the major achievements of Donald Trump’s first term was Operation Warp Speed, the $18 billion effort to accelerate the development of a vaccine against the coronavirus. He deserves credit for supporting this great effort, the millions of lives it helped save, and the enormous economic benefits it brought. So why would he now appoint someone who would undo his own success?

In his election night victory speech, Trump hinted that Robert F. Kennedy Jr. — a well-known vaccine opponent and purveyor of science fake news — would have a prominent role in his administration. But that would be a catastrophic mistake that would cause the deaths of countless Americans while also damaging Trump’s political standing and tarnishing the legacy of his first term.

Trump should remember that Kennedy spread lies about the coronavirus vaccine, falsely calling it the “deadliest vaccine ever created.” In any position of influence, Kennedy would jeopardize the difficult progress that has been made in public health and put American lives at unnecessary risk.

Kennedy, the nephew of the 35th US president, has no experience in public health. He is an environmental lawyer who has decades of experience doing good work in battles against polluting companies. In the early 2000s, however, he began exploring the dark corners of pseudoscience, including the baseless and debunked conspiracy theory that common childhood vaccines are linked to autism. His list of absurd public health positions has grown to include drinking water fluoridation. But of all his crazy ideas, vaccine denial is the most dangerous.

Immunizations are one of the greatest public health achievements of the 20th century, saving millions of lives in the US and around the world. Study found that infants accounted for two-thirds of the 154 million lives saved by international vaccination efforts over the past half century. Thanks to vaccines, diseases such as polio are now rare and smallpox has been eradicated.

Kennedy would jeopardize all that progress. Anyone want to experience the return of measles, mumps and rubella to the nation’s schools? Then let Kennedy be appointed. Do you want to see more people die from coronavirus? Let Kennedy be appointed then. Do you want diphtheria to rise? Let Kennedy be appointed then.

The fact that most Americans can’t tell what causes diseases like diphtheria and rubella is a testament to the success of vaccines. Diminishing public support for them—and for future vaccine developments—would have disastrous consequences.

I grew up at a time when one of the greatest fears of parents was that their children might contract polio, which killed thousands of people before the advent of the vaccine in 1955. Back then, if someone told us that anyone who opposed vaccines for terminal diseases can be considered a candidate for a high government position, we would think that person was hallucinating or deranged.

Parents who remain angry — and rightfully so — about school closings and mask mandates aren’t expecting a return of polio and measles. Unfortunately, Kennedy’s agenda will bring about just that.

Kennedy is now trying to claim that he is not anti-vaccine, but his own words prove otherwise. “There is no vaccine that is safe and effective,” he said in July. He couldn’t have made a bigger mistake. There is no scientific basis for his attacks on vaccine safety, and the false doubts he sows have already caused tremendous damage to families.

The anti-vaccine movement in which he has played a major role has decreased the use of vaccines and increased deaths from vaccine-preventable diseases. Measles, a highly contagious and potentially fatal virus, was declared eliminated in the US in 2000. But in 2024, more than 270 cases have been reported in 30 states.

It is unclear what role Kennedy might play in a second Trump administration. To serve as health secretary or head of the Food and Drug Administration (FDA) would require Senate approval. Senate Republicans, especially centrists who want to play a major role over the next four years, should quietly but forcefully send a clear message to the president-elect: Don’t send us Bobby.

Trump could still appoint him to an advisory role within the White House, but he would have to recognize how damaging that would be — not only to the health of Americans, but also to his own legacy.

Through his support for Operation Warp Speed, Trump helped bring about one of the greatest scientific breakthroughs of the 21st century. He should be bragging about this achievement, not undermining it. The best decision of his second term could be to remove Kennedy from the list of candidates for a role in his administration.

Michael R. Bloomberg is founder and principal owner of Bloomberg LP, the parent company of Bloomberg News, UN Special Envoy for Climate Ambition and Solutions, and Chairman of the Defense Innovation Council. He also contributes to the Bloomberg Opinion column