Even as the Covid wave in Florida continues, Gov. Ron DeSantis' administration is once again advising against the mRNA vaccines: this time in the most vulnerable residents.

In updated guidance for health care providers released Thursday, the Florida Health Department and state Surgeon General Joseph Ladapo questioned the safety and effectiveness of the mRNA Covid vaccines from Pfizer and Moderna, including for older adults and people with underlying health problems. "Any provider concerned about the health risks associated with Covid-19 for patients over the age of 65 or with underlying health conditions should prioritize patient access to non-mRNA Covid-19 vaccines and treatment," according to the state guidance.

Standing in opposition to advice from federal health agencies and other medical experts about the safety of the Covid vaccines, the Florida Health Department said the recommendation was based on high rates of immunity from prior infections and "currently available data."

Without noting the high risk of serious Covid infection or hospitalization for older adults, the guidance listed safety concerns for the mRNA vaccines, including the risk of a rare heart condition called myocarditis, as well as the risk of POTS, or postural orthostatic tachycardia syndrome, a debilitating heart condition. 

Numerous studies have shown that both Pfizer and Moderna's vaccines are indeed associated with a small but increased risk of myocarditis. However, most cases occur in young men and most people make a full recovery. Studies have also shown that the risk of myocarditis is much higher with a Covid infection and is often more severe than the vaccine-associated condition.

A study published in Nature Cardiovascular Research​ also found that people diagnosed with Covid are five times more likely to develop POTS after infection than after Covid vaccination, emphasizing the importance of the vaccine.

Dr. Paul Offit, a vaccine expert at Children's Hospital of Philadelphia, said the Florida surgeon general's guidance is unnecessarily alarming people about the Covid vaccines.

"It's just such a dangerous game he plays," said Offit, who has served on the FDA's independent vaccine advisory committee. "You only have a roughly 1,000 times greater likelihood of dying [from Covid] if you're over 65 than if you're under 18."

"The mRNA vaccines are remarkably safe," he added.

New doses of the Pfizer and Moderna vaccines were approved by the Food and Drug Administration in August. They're targeted to the KP.2 version of the steadily mutating virus and should provide good protection against severe illness, hospitalization and death, experts say. 

The United States offers only one Covid vaccine that isn't mRNA-based: Novavax. Novavax's traditional protein-based shot offers an alternative vaccine technology to mRNA.  

In a statement, a Novavax spokesperson said its updated vaccine is now available at thousands of retail and pharmacy locations nationwide.

The Florida Health Department did not immediately respond to a request for additional comment. 

Dr. Isaac Bogoch, an infectious disease specialist at the University of Toronto, called Florida's recommendation "unfortunate," saying it could put older adults and people with underlying health conditions at risk.

"While the vaccine does not protect against infection nearly as well as it once did, there is very good data demonstrating how Covid vaccines can reduce the risk of severe manifestations of the virus in those who are at greatest risk," said Boguch, who has no ties to the vaccine makers. 

Covid cases remain high in the U.S. following a summer wave. Wastewater data collected between Aug. 25 and Aug. 31 shows that 23 states -- including Florida -- are reporting "very high" levels of the virus, according to the CDC. Emergency department visits and hospitalizations remain elevated as well, although they're showing signs of declining. In Florida nursing homes, after declining from summer highs, Covid infections are ticking up again, according to CDC data. 

The CDC currently recommends everyone ages 6 months and older get an updated Covid vaccine this fall from any of the three options. 

This isn't the first time Ladapo has ignored CDC guidance. Last year, Ladapo also recommended that Florida residents under the age of 65 not get the mRNA Covid vaccines, citing widespread immunity and "questions we have about safety and about effectiveness."

"My judgment is that it's not a good decision for young people and for people who are not at high risk at this point in the pandemic," he said.