(NEW YORK) — A former Florida surgeon general is rebuking claims by the DeSantis administration that updated COVID-19 vaccines have “not been proven to be safe or effective” and that the shots should not be recommended for individuals under the age of 65.

The COVID vaccines remain “very, very safe, and have a really proven efficacy, particularly against preventing severe disease,” Dr. Scott Rivkees, the former Florida surgeon general during the initial years of the pandemic, told ABC News.

“If they say that COVID vaccines are not safe and that they are not effective, the onus is on them to show those data,” Rivkees said.

Everyone over the age of 6 months is recommended to receive an updated COVID vaccine, according to recommendations made by federal health authorities this week.

“I will not stand by and let the FDA and CDC use healthy Floridians as guinea pigs for new booster shots that have not been proven to be safe or effective,” Gov. Ron DeSantis said in a statement Wednesday. “Once again, Florida is the first state in the nation to stand up and provide guidance based on truth, not Washington edicts.”

The Centers for Disease Control and Prevention director Dr. Mandy Cohen defended the updated COVID-19 vaccines saying in a statement that the shots “are proven safe; they are effective, and they have been thoroughly and independently reviewed by the FDA and CDC.”

“Public health experts are in broad agreement about these facts, and efforts to undercut vaccine uptake are unfounded and dangerous,” the statement added.

The Food and Drug Administration told ABC News in a statement that these were not new vaccines being offered.

“To clarify, these are not “new vaccines”…COVID-19 vaccines have undergone—and continue to undergo—the most intense vaccine safety monitoring in U.S. history. Additionally, COVID-19 vaccines have an established track record of safety and effectiveness, from the large-scale clinical trials conducted prior to initial authorization and licensure to real world evidence following their use,” the FDA said in part of a statement provided to ABC News.

Rivkees points to CDC data showing that about 25% of COVID deaths in the state of Florida were in individuals under the age of 65. While there remains a lower risk of severe illness in younger populations, the benefits of protection from a vaccine outweigh any potential risks, federal health authorities say.

“When you look at the data, particularly the pediatric data of younger individuals who gets severe COVID to the point where they can succumb to the virus, more than half of those individuals don’t have underlying medical conditions,” Rivkees said.

Last October, current Florida Surgeon General Dr. Joseph Ladapo wrote on X that an analysis by the Florida Department of Health “showed an increase risk of cardiac-related death among men 18-39 following COVID vaccinations.”

The analysis came under scrutiny within the scientific community, with many vaccine experts calling the study poorly designed and dangerously misleading.

Ladapo came under further scrutiny earlier this year after the Tampa Bay Times obtained drafts of his analysis indicating Lapado allegedly omitted data to suggest vaccines pose a higher health risk for young men than they really do.

At the time, Ladapo released a statement to Politico, which also published the drafts, reading: “To say that I ‘removed an analysis’ for a particular outcome is an implicit denial of the fact that the public has been the recipient of biased data and interpretations since the beginning of the mRNA COVID-19 vaccine campaign.”

Ladapo had also issued guidance last year that children may not benefit from COVID vaccines due to limited risk of severe illness, existing immunity, and the potential risk of myocarditis.

“It’s not clear that the previous concerns expressed by Ladapo about myocarditis have solid footing,” Rivkees added.

Myocarditis is inflammation of the heart muscle, according to the CDC. It has been rarely reported and has typically occurred in young adult males within several days after COVID vaccination, according to the agency.

“The data clearly showed that in individuals, risk of myocarditis is much, much greater from COVID, than from the vaccine. And the data that were recently presented at the [CDC] meeting, show that with the boosters that were out this last fall that the risk of myocarditis was extraordinarily rare,” Rivkees said.

More than 80,000 people have died in the state of Florida from COVID-19, and some of those deaths could have been prevented by vaccines, Rivkees said.

“Those of us in public health, those of us in health care should do everything we can to keep individuals safe and healthy, especially when these vaccines have such a great safety profile,” Rivkees said.

ABC News’ Will McDuffie and Hannah Demissie contributed to this report.

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