We've grown accustomed to provocative statements by the Republican presidential candidate Donald J. Trump. So when he says that if elected Robert F. Kennedy Jr. can "go wild on health ... go wild on the medicines" it seems designed to trigger opponents and elicit a negative emotional response. Yet at the same time it must be taken seriously in light of what Kennedy now says, namely that Trump has promised him "control" over public health agencies in America.

Known for espousing conspiracy theories related to health, particularly vaccines, Kennedy appears to be angling for a cabinet role in a possible second Trump Administration, according to NBC News. Kennedy has talked about dismantling core functions of certain agencies under the Department of Health and Human Services, which he says are captured by corporations like the pharmaceutical companies. Take, for instance, what Kennedy posted on X last week, warning the Food and Drug Administration that its "aggressive suppression of psychedelics, peptides, stem cells, raw milk, hyperbaric therapies, chelating compounds, ivermectin, [and] hydroxychloroquine" was about to end.

The drugs ivermectin and hydroxychloroquine caught my attention, as they were embroiled in a culture war during the Covid-19 pandemic that pitted unproven treatments against proven measures, such as vaccines.

But perhaps more ominously, the Covid-19 pandemic seems to have brought out vaccine skeptics like Kennedy in full force, not only toward coronavirus vaccines but also traditional childhood immunizations, like those targeting polio, tetanus and measles.

From smallpox inoculations -- which began in the late 18th century and ended when the disease was eradicated in the 1970s -- to mumps, rubella, tetanus, diphtheria, polio and measles immunizations, vaccinations have saved millions of lives and prevented crippling and life-threatening illnesses from occurring.

To illustrate, mass vaccination programs with single or combination -- measles, mumps and rubella -- shots began in the 1960s and quickly suppressed the spread of measles in most developed countries. The measles vaccine is "sterilizing," which means it not only prevents illness, but also transmission.

Nevertheless, there have periodically been upticks in childhood vaccine hesitancy. In the United Kingdom, for example, vaccination rates dipped in the early 2000s after false claims of a link between the MMR jab and autism were posted in the media.

Andrew Wakefield's campaign in the U.K. and globally at the turn of the millennium to connect the MMR shot to autism provides an infamous illustration of how the anti-vaccine community operates. While such claims were unsupported by evidence, Wakefield's trusted position as a physician-scientist helped his assertions dominate headlines, leaving a legacy of harm that persists even today, long after his work was exposed as fraudulent.

Despite the debunking of Wakefield's allegations, Kennedy became a prominent American figure misinforming the public by continuing to maintain that there's a link between childhood vaccines and autism. He joined the Children's Health Defense organization ten years ago as a founding member of its board. Later he became its chairman. CHD is accused of pushing discredited conspiracy theories linking conditions like autism with vaccines and other environmental factors. As recently as August 2023, Kennedy went on Joe Rogan's popular podcast insisting on there being a connection.

And on Rogan's shows and elsewhere Kennedy has backed a number of Covid-19 vaccine conspiracy theories. In December 2021, Kennedy went so far as to call the Covid-19 vaccine the "deadliest vaccine ever made," citing deaths reported to the Vaccine Adverse Event Reporting System. Such reports do not constitute documented evidence that a vaccine caused the event. Nonetheless, Kennedy did not retract his statement.

Peter Hotez, a renowned researcher and professor of pediatrics, molecular virology and microbiology at the Baylor College of Medicine, has long contended that 200,000 unvaccinated Americans needlessly died during the Covid-19 Delta and BA.1 Omicron waves in 2021 and 2022. Many, in his view, refused the vaccine because of widespread disinformation. Hotez describes this in his book The Deadly Rise of Anti-Science.

Also, critics of Kennedy assert that his actions led to 5,700 Samoans contracting measles in 2019; 83 of them, mainly young children, died. He has denied any responsibility. But the anti-vaccine entity CHD, which he has led, did help spread misinformation in Samoa that contributed to a decline in the measles vaccination rate which preceded the outbreak.

Since running for president and subsequently endorsing Trump, Kennedy has tried to distance himself from the anti-vaccine movement. But this is hard to square with the entity he's aligned with, the CHD, and statements he's made, such as "no vaccine is safe and effective."

Kennedy defends himself as merely wanting placebo-controlled trials prior to licensure and no vaccine mandates. However, the vaccines he rails against are typically subject to such clinical trials. Furthermore, arguably the mandates Kennedy opposes, which have been in place since the 1960s, have helped to contribute to a dramatic decline in childhood infectious diseases.