Politifact and Kaiser Health News fact-check Sen. Rand Paul's assertions about mask wearing, find them to be "half-true'

U.S. Sen. Rand Paul has become known for his squabbles with infectious-disease expert Dr. Anthony Fauci, most recently at a Senate hearing when Paul insisted that people don't need to wear a mask if they have had Covid-19 or had the vaccine, contrary to Fauci's advice and personal practice.

Paul said it is "theater" for Fauci to wear masks because he has been vaccinated. Fauci disagreed, noting that new variants of the coronavirus are circulating in the U.S. and in other countries.  

A few days later, Paul tweeted, "Sorry, Dr. Fauci and other fearmongers, new study shows vaccines and naturally acquired immunity DO effectively neutralize Covid variants. Good news for everyone but bureaucrats and petty tyrants!" The tweet linked to a study published by JAMA Network. 

After asking the experts: "Are covid variants effectively neutralized by vaccines or natural immunity conferred on people who recover from the illness?"  Kaiser Health News and Politifact ruled Paul's assertion to be "half-true" and explained how they came to that conclusion. 

"In short, the research cited by Paul does show good blood levels of neutralizing antibodies against at least some of the current variants following infection or vaccination. But they’re not the whole story," Julie Appleby reports for Kaiser. 

Mehul S. Suthar of Emory University's vaccine center, an author of the study Paul cited, told Appleby that the results are encouraging but should not be seen as all-encompassing: “Our interpretation is that our study looks at one aspect of immune response, antibodies.” 

Small samples; multiple variants; other considerations

The study looked at blood samples from 40 people who had recovered from Covid-19, as well as blood samples from 14 people who had gotten both doses of the Modena vaccine.

The researchers ran tests on those samples against the original coronavirus and three variants, including B.1.1.7, which first appeared in the United Kingdom and is circulating in the U.S. 

Suthar told Appleby that the antibodies produced from being infected or being vaccinated "appear to work well" against B.1.1.7, but Appleby notes there are caveats. 

The results were based on a small number of samples, antibodies are just one measure of how how a person's body protects itself against disease, and the analysis did not include other variants of concern, like those first identified in South Africa and Brazil, Appleby notes. 

In addition, she writes, there are other factors in the "real world" that must be considered like which variant a person is exposed to, or whether masks and good ventilation were involved. 

“Part of the reason that real-world data are so important is looking at the whole picture of immunity,” Gigi Gronvall, a senior scholar at Johns Hopkins Bloomberg School of Public Health, told Appleby. “With the level of community transmissions of disease, I would be concerned that there will be more variants.” 

Blanket assertions and a mutating virus

“Blanket assertions made by non-scientific experts are not going to help,” said Gronvall.

Dr. Jesse Goodman, professor of medicine and a specialist in infectious diseases at Georgetown University, agreed:  “It’s wrong to declare victory and say there’s no problem with variants and that everyone previously infected will be fine." 

Kaiser notes that viruses naturally mutate as they replicate, and reports, "Lab tests on blood samples from vaccine trial participants in South Africa showed lower levels of neutralizing antibody production, possibly related to the variant circulating there."

Goodman told Appleby, “We expect vaccines and prior infection to offer significant protection against variants that are closely related. But as they become more genetically different — like the South African one — that protection could go down.” 

The vaccines are also designed to prevent hospitalization and death, not to prevent infection, Appleby notes. "Don’t assume, as Paul’s tweet implies, that recovering from covid or getting vaccinated means zero risk of infection. For one thing, reinfection is rare but can occur," she writes.

Goodman pointed to a recent study conducted in Denmark showing that a very small percentage (0.65%) of people who tested positive for Covid-19 in the spring fell ill again. 

The ruling: Half true

"Paul is correct that the JAMA study showed vaccination or previous infection appeared, based on a small sample of people, to help neutralize the virus," Appleby writes. "However, he left out important details that make his position an oversimplification of a complicated issue." 

Again, she noted that the study only considered one variant, only looked at one factor that protects against disease and did not factor in real world circumstances. "So, for those reasons, we rate the senator's statement Half True."

Politifact's other ratings for statements by for on behalf of political figures are Mostly True, Mostly False, True, False and Pants on Fire.