lorida's Surgeon General Joseph A. Ladapo warned on Friday against young men receiving COVID-19 vaccines, citing a disputed analysis by the state health department that they pose an "abnormally high risk" of death.
"Today, we released an analysis on COVID-19 mRNA vaccines the public needs to be aware of. This analysis showed an increased risk of cardiac-related death among men 18-39. FL will not be silent on the truth," Ladapo tweeted.
The state's health department released a statement on Friday stating that it carried out an analysis using a self-controlled case series technique to evaluate vaccine safety. The analysis, which was not peer-reviewed, has been criticized by vaccine experts, who said that it was flawed and the benefits of the vaccine outweighed the risks.
Twitter blocked the post from Ladapo, an outspoken skeptic of COVID-19 vaccines, before restoring it on Sunday morning.
The Florida health department said that the analysis showed that there is an 84 percent increase in "relative incidence of cardiac-related death among males 18-39 years old within 28 days" after vaccination that contains messenger RNA (mRNA), which is used in the Pfizer-BioNTech and the Moderna vaccines.
The analysis clarified that COVID-19 vaccination was associated with a "modestly increased risk for cardiac-related mortality" 28 days after receiving the vaccine.
The primary analysis was conducted on Floridians who were 18 years and older "who died within 25-weeks of COVID-19 vaccination" since the vaccines were first rolled out in December 2020.
However, the analysis excluded individuals who had a confirmed COVID-19 infection, received a booster or received their last COVID-19 vaccination after December 8, 2021. The study concluded on June 1.
"Individuals with preexisting cardiac conditions, such as myocarditis and pericarditis, should take particular caution when considering vaccination and discuss with their health care provider," the state's health department said in the statement.
"Based on currently available data, patients should be informed of the possible cardiac complications that can arise after receiving a mRNA COVID-19 vaccine. With a high level of global immunity to COVID-19, the benefit of vaccination is likely outweighed by this abnormally high risk of cardiac related death among men in this age group," it added as new guidelines.
The analysis said that men over 60 years old had a 10 percent increased risk of cardiac-related death within 28 days of receiving vaccines that contain mRNA. It also said that vaccines without mRNA didn't have these increased risks among any population.
Daniel Salmon, director of the Institute for Vaccine Safety, told Newsweek on Saturday that the paper, which has not been peer-reviewed, lacks enough details to truly assess what has been done in this study and the validity of its findings.
"mRNA COVID-19 vaccines have been shown to cause myocarditis with the highest risk among younger males after the 2nd dose. In general, vaccine induced myocarditis seems milder than other types of myocarditis. There have a been a few reports of post-vaccination myocarditis deaths globally, but this seems to be exceedingly rare. Even among the highest risks groups for post-vaccination myocarditis, the benefits of the vaccines still outweigh the risks," Salmon said.
Dr. Deepti Gurdasani, a clinical epidemiologist and statistical geneticist at Queen Mary University of London, wrote on Twitter: "It took me six reads to even start to understand what the authors had done, because the methodology makes little to no sense in many ways."
She said in a subsequent post: "Vaccines have saved millions of lives, and are continuing to. Do they have side effects- yes, they are rare, but they do happen. It's a benefit-risk calculation. However, this study tells us nothing about the risks or the benefits. It's incredibly flawed."
In April, the Centers for Disease Control and Prevention (CDC) released a report that said cardiac complications, especially myocarditis and pericarditis, have been connected with COVID-19 infection and mRNA COVID-19 vaccination.
The agency said that cases of myocarditis or pericarditis were "calculated" after unspecified doses of mRNA Pfizer and Moderna COVID vaccines in an effort to compare the risk for cardiac outcomes after COVID infections to after vaccines.
"The incidence of cardiac outcomes after mRNA COVID-19 vaccination was highest for males aged 12–17 years after the second vaccine dose; however, within this demographic group, the risk for cardiac outcomes was 1.8–5.6 times as high after SARS-CoV-2 infection than after the second vaccine dose," the CDC said in the report.
As of Friday, over 110 million people in the United States have received the first COVID vaccine booster dose, according to the CDC's data tracker.
Newsweek reached out to the Florida Department of Health, the Immunization Action Coalition, the Galveston National Laboratory, and vaccine experts Ruth Karron and Joshua M. Sharfstein with the Johns Hopkins' Bloomberg School of Public Health.
Update 10/9/2022, 3:05 p.m. ET: This article has been updated to include comments from Daniel Salmon, director of the Institute for Vaccine Safety.
Update: 10/10/2022, 5:47 a.m. ET: This article has been updated with additional context and comment.