Mask guidance for vaccinated people is based in science

U.S. Sen. Ted Cruz, R-Texas, took to Twitter Tuesday to challenge the latest coronavirus guidance as vaccines were being distributed around the country.

Cruz responded specifically to Dr. Vin Gupta, a lung and intensive care unit doctor who appeared on MSNBC to caution vaccine recipients against abandoning the kinds of preventative measures public health experts have been emphasizing all year.  

"This is one of the misperceptions here: just because you get vaccinated with a second dose, it does not mean you should be participating in things like traveling in the middle of an out-of-control pandemic or that you’re liberated from masks," Gupta told MSNBC’s Chuck Todd. "Everything still applies until all of us get the two-dose regimen, and we don’t think that’s going to happen until June or July." 

Many unknowns surround the COVID-19 vaccines from Pfizer and Moderna. For instance, it’s unclear if vaccinations strictly protect infected people from serious illness, or if they also prevent people from getting infected, Gupta said.

"Don’t let your guard down just because you got vaccinated," he said. "You might be able to get infected by the virus and pass it on to others."

The comment was enough to peeve Cruz, who has previously criticized guidance to wear masks and other measures to prevent the spread of COVID-19.

"This is a bizarre, lunatic, totalitarian cult," Cruz said in a tweet responsive to Gupta’s mask-wearing advice. "It’s not about vaccines or protecting people’s lives — it is instead profoundly anti-science, and is only focused on absolute govt control of every aspect of our lives."

In July, Cruz faced criticism after he was photographed maskless on an American Airlines flight one month after the airline required passengers to wear face masks while onboard planes.

Cruz stirred controversy again when he called Sen. Sherrod Brown, D-Ohio, "a complete ass" for asking a fellow senator to wear a mask while speaking. And in November, as Texas public health officials urged people to avoid large holiday gatherings as daily case numbers reached record highs, Cruz tweeted a graphic with the words "Come and take it" beneath a Thanksgiving turkey.

So is the latest round of COVID-19 guidance — urging continued mask-wearing and discouraging travel — "profoundly anti-science" as Cruz claims?

"I think [Cruz] is talking beyond his knowledge," said Dr. Jaquelin Dudley, professor of molecular biosciences and associate director of the LaMontagne Center for Infectious Disease at the University of Texas.

"This whole thing about mask-wearing, taking a vaccine and social distancing has somehow become a political football instead of, let's just talk about what we know and what we don't know," she said.

Cruz’s office did not respond to a request for clarification on precisely what the senator meant by "anti-science." And a spokesperson for the Institute for Health Metrics and Evaluation, the organization for which Gupta works, declined to address Cruz’s comments in an effort to remain apolitical. ("With the issue at hand — responding to comments by a U.S. senator stating that protective measures against COVID-19 constitute "bizarre, lunatic, totalitarian cult" — it would be impossible to make this apolitical," a spokesperson said.)

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But the guidance highlighted by Gupta is the same messaging that has come from the very top level of the U.S. coronavirus response apparatus. On Monday, Dr. Anthony Fauci, President Donald Trump’s top adviser on the coronavirus crisis, spoke before an online audience and gave the same cautionary advice.

"It’s not going to be like turning a light switch on and off. It’s not going to be overnight. It’s going to be gradual. ... I don’t believe we’re going to be able to throw the masks away and forget about physical separation and congregant settings for a while, probably likely until we get into the late fall and early next winter, but I think we can do it," he said.

The Centers for Disease Control and Prevention also advises that there is not enough information "to say if or when CDC will stop recommending that people wear masks and avoid close contact with others," suggesting that more time is needed for experts to understand how the virus will respond to vaccinated persons.

According to Dr. Jonathan Temte of the University of Wisconsin School of Medicine and Public Health, the clinical trials of the vaccine have only looked at how the vaccine prevents illness. Those trials didn’t provide any information on transmission, meaning that vaccinated people could still carry and spread the virus.

It takes repeat exposures for the immune system to learn how to best fight off a virus, which is why COVID-19 vaccinations require two doses about three weeks apart, according to the CDC. Clinical trials through the National Institutes of Health tell us that the immune system begins to create a beta version of antibodies after a person receives the first dose of the vaccine. These are the body’s least optimal version of these antibodies. Phase III trials — which test for vaccine efficacy — indicate these initial antibodies are capable of fighting off severe illness caused by the virus, but may be less capable of preventing the virus’ spread. 

A second dose of the vaccine helps the body create a new version of antibodies more honed in on fighting COVID-19. A person’s immune system is most capable of fighting off COVID-19 about one month after the initial dose of vaccine. 

"Your body learns. You can’t assume that on day one after the vaccine you’re going to be protected and you’re not going to be able to spread the infection," Dudley said.

"We don’t have that data yet. There’s been so many things to learn," she said.

This is one of the primary sources of uncertainty surrounding the vaccine: whether vaccinated people can be contagious. If vaccinations protect only against illness and not transmissions, achieving herd immunity through vaccination becomes more difficult, according to the peer-reviewed medical journal The Lancet.

"Pfizer and Moderna together project that there will be enough vaccines for 35 million individuals in 2020, and perhaps up to 1 billion in 2021," The Lancet wrote. "As a result, many millions of people at high risk of disease will not be immunized any time soon, necessitating the continued use of non-pharmaceutical interventions."

Furthermore, it’s also unknown how long immunity will last in a vaccinated person, or how effective vaccination will be in older people or those with underlying comorbidities.

The guidance issued by the CDC that urges vaccinated people to continue wearing masks and avoid travel was described by Cruz as "profoundly anti-science."

The emerging vaccines each were placed through months of clinical trials that tested for their efficacy in preventing illness. Their efficacy in preventing transmission was not part of the trials and is not yet known. The guidance issued by the public health community is borne out of science’s blind spots in regard to transmission and the gradual pace of vaccine distribution.

We rate this claim Pants on Fire.