DeSantis says natural immunity is equal to vaccines. Experts say it’s not so simple

As Florida Gov. Ron DeSantis intensifies his fight against the Biden administration’s new vaccine requirements, he’s focused some of his attacks on one main claim: Federal authorities are ignoring the benefits of natural immunity against COVID-19 reinfections.

“You can’t tell noble lies to try to get [people] to behave in a way that you think you want them to behave in. And so we see that time and time again in this issue of natural immunity,” DeSantis said on Tuesday as he introduced the state’s new surgeon general, who will lead the Florida Department of Health through the response to the coronavirus pandemic.

While DeSantis has repeated his stance on natural immunity for months, Dr. Joseph Ladapo, Florida’s new top health official, wasted no time to say “there’s tremendous data that supports that natural immunity protects people from getting very ill and also protects people from being infected again.”

The issue of natural immunity is just one in a string of political battles waged by DeSantis during the pandemic, looking ahead to 2022 and a still unannounced reelection campaign. DeSantis’ early pandemic policies last year drove closures around the state and placed Florida’s vulnerable elderly at the front of the vaccination line. But since then, he has positioned himself as the leader of the Republican resistance to strict measures and mandates pushed by President Joe Biden, suggesting Florida is being punished by the federal government, portraying himself as the protector of “individual rights” and focusing on early treatment instead of prevention.

In the past several months, DeSantis’ administration has fought local school districts on mandating masks, withholding money equivalent to the monthly salaries of school board members in at least two districts, despite an investigation from the U.S. Department of Education. On Wednesday, Ladapo issued a new rule that would give parents sole discretion on whether they want to quarantine their children after an exposure to COVID-19.

But with natural immunity, an argument against vaccination that has been previously cited by lawmakers like Wisconsin Congressman Ron Johnson, the truth is not so simple. Infectious disease experts and vaccine researchers agree it’s way too soon to make declarative statements that ignore the risk of severe illness and omit the mountain of caveats that come with a novel virus that mutates rapidly and which scientists are still struggling to understand.

“Anyone who tells you that they know exactly what’s going on shouldn’t be trusted, because we don’t,” said Sumit Chanda, an infectious disease expert with Scripps Research who studies how pathogens infect cells and the immune system responds.

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The Israel study

On Sept. 13, DeSantis cited a study from Israel and a separate study from the Cleveland Clinic to assert that first responders who recovered from COVID-19 have “very strong immunity. That’s very clear.” And there is some, albeit early, evidence to suggest natural immunity is strong.

Asked for the studies the governor relied on for his statements, Press Secretary Christina Pushaw provided links to the studies from Israel and the Cleveland Clinic, as well as a link to an article in Science magazine about the Israeli study.

The Cleveland Clinic study surveyed more than 50,000 employees and compared four groups based on their history of infection and vaccination status. None of more than 1,300 unvaccinated employees who had a prior infection tested positive during the five months of the study.

The study concluded: “Individuals who have had SARS-CoV-2 infection are unlikely to benefit from COVID-19 vaccination, and vaccines can be safely prioritized to those who have not been infected before.”

The study from Israel relied on the database of Maccabi Healthcare Services, a provider which has enrolled more than 2.5 million Israelis. The study concluded that natural immunity provides “longer lasting and stronger protection against infection, symptomatic disease and hospitalization caused by the delta variant” than vaccination with the two-dose Pfizer-BioNTech vaccine.

“The governor has always said that natural immunity is at least comparable to vaccine immunity, in terms of strength and amount of time conferred,” Pushaw said in an email.

But the Israel study notes that it has several limitations that could have influenced the findings, including the fact that testing was voluntary and may underestimate people with asymptomatic infections, who may not get tested, or those who may have previously had COVID-19 and believe they are immune.

For researchers like Chanda, whose work helped discover how HIV suppresses the immune response, sweeping declarations about COVID-19 immunity when the science on that topic is still unfolding raises a red flag.

“You can’t unequivocally say that,” he said. “This is the issue with what these guys say. There’s a modicum of truth to what they’re saying but it’s not a generalize-able, actionable type of statement.”

Earlier this month, the Biden administration announced one of its most sweeping vaccine rules yet, which affects millions of people in the U.S. The Department of Labor’s Occupational Safety and Health Administration would require businesses with more than 100 employees to confirm all of their workers are fully vaccinated, or otherwise require them to submit to weekly COVID tests.

The measure follows other mandates across the federal government, including a memo from the Pentagon in August that requires vaccination for all members of the military. DeSantis has called Biden’s new rules “unconstitutional” and has vowed to fight them.

“They think if you tell people, ‘Recovery from COVID provides strong protection,’ that some people will say, ‘Oh, I might as well just go get infected, I have that.’ And I don’t think that most people would do it but even if someone does, you have to say the truth to people,” DeSantis said of the federal government on Tuesday.

Chanda pointed out that the studies from Israel and the Cleveland Clinic cited by DeSantis are both so-called pre-prints that have not been peer reviewed, which means they have not been evaluated and should not be used to guide the clinical practice of medicine.

“What they need to do is come in with a breadth of literature. That’s what scientific consensus is, you reach a critical mass of data,” he said. “Until then we’re just amassing data. That’s like saying at halftime the score is this so we know what the final score will be. … You have to play all four quarters before we declare a winner and a loser.”

Dr. Maria Alcaide, an infectious disease specialist with the University of Miami Miller School of Medicine, said the answer to whether natural immunity confers stronger protection than vaccination alone will depend on many moving parts, including the severity of the disease, the quality of the immune response, and the prevalence of mutations that can evade protection.

In general, she said, reinfection is very unlikely to happen within 90 days of infection with a specific variant.

“After that time,” she said, “immunity will start going down. Chances of having a new infection will increase, but also at that time there may be new variants that are circulating.”

Alcaide, who was also a co-investigator for the Moderna COVID-19 vaccine clinical trials in South Florida, said scientists are still working to answer the question of what confers the strongest protection: natural infection or vaccination or a combination of both.

“We don’t know yet what is better,” she said. “I think we are seeing all possible combinations happening. We know all of those will confer protection. We don’t know how long the protection lasts, and we don’t know if that protection is lifelong or not.”

Immunity to SARS-CoV-2, the virus that causes COVID-19, also depends on the severity of the illness, the individual’s immune response, and the quality of the antibodies the body deploys to neutralize the virus and keep it from replicating.

Chanda, whose research also focuses on influenza, dengue virus and HIV, said all natural infections are not the same.

“If you get a mild case of COVID, it’s going to be unlikely that you’re going to get the vigorous antibody response you need for long-term protection,” he said. “If you get severe disease, where you’re in the hospital, I would say, yeah, you probably have some level of protection. The question is how long does protection last? How long before it wanes? These are questions we don’t know the answers to. There’s no data.”

Fauci on natural immunity

Still, DeSantis has said he believes the federal government is not talking enough about natural immunity, which he thinks should be taken into consideration before enforcing vaccine mandates at workplaces and in schools. But the Biden administration has shown some signs in the past several weeks that it is following data on natural immunity, despite believing there’s still not enough information to know how durable natural immunity can be.

Dr. Anthony Fauci, Biden’s top health adviser, told “Meet The Press” host Chuck Todd last Sunday that “there’s no doubt” that when someone is infected, they can get strong immunity. But that getting vaccinated after an infection can provide even higher protection.

“We’re following that, but not yet... the durability is unclear,” Fauci told Todd. “There’s another fact we know that, if you do get infected and recover and get vaccinated, the level of your immunity is extraordinarily high, surpassing any of the other two-dose vaccines that you get.”

The current recommendation from the Centers for Disease Control and Prevention is that those who’ve recovered from the disease should still get the shots.

In a separate interview with CNN’s Sanjay Gupta, Fauci addressed the limitations of the Israel study, saying “the one thing the paper from Israel didn’t tell you is whether or not as high as the protection is with natural infection, what’s the durability compared to the durability of the vaccine.”

Though DeSantis has touted the importance of natural immunity to COVID-19, Florida does not report any data on people who have had previous infections. Some states track and report COVID-19 reinfections, including Colorado and New Mexico. A spokesperson for the Florida Department of Health did not immediately respond to questions about whether Florida is internally tracking reinfections or if they plan to do so.

To put in perspective the amount of data necessary to reach a consensus on the significance of natural immunity, Chanda noted that SARS-CoV-2 did not exist more than two years ago, a virtual infant among viruses that have been studied for decades or longer.

“My problem is they’re making declarative policy on things we don’t have an answer to,” he added. “If we find that natural immunity is stronger, even if you have a mild infection, then great. But until then, I think the safest thing for people to do is double down on a vaccine that’s as safe as anything else that you’ll put in your body.”

Miami Herald Tallahassee Bureau Chief Mary Ellen Klas contributed to this report.