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Bill McCarthy
By Bill McCarthy April 15, 2021

Tucker Carlson falsely claims COVID-19 vaccines might not work

If Your Time is short

  • Clinical trials and real-world studies have shown the available COVID-19 vaccines to be effective at protecting against COVID-19 infections and severe symptoms.

  • Responding to Fox News host Tucker Carlson’s suggestion that the vaccines might not work, Dr. Anthony Fauci said the clinical trials showed “an overwhelming signal of efficacy.” 

  • The CDC still recommends that fully vaccinated people wear masks and keep their distance in public spaces. There are legitimate reasons for that, experts said, including the fact that many Americans have not yet been vaccinated.

In a comment that Dr. Anthony Fauci, the nation’s top infectious disease expert, rejected as a "crazy conspiracy theory," Fox News host Tucker Carlson suggested to his millions of viewers that the COVID-19 vaccines might not work.

Clinical trials and real-world studies have shown the available vaccines are effective at protecting against COVID-19 infections and severe symptoms, despite Carlson’s claim.

The Fox News host opened his April 13 segment by talking about the recent recommendation by federal regulatory agencies to pause use of the Johnson & Johnson vaccine, one of three vaccines approved for emergency use in the U.S. The agencies are investigating six reports of a rare but severe type of blood clot among the more than 6.8 million people who got the shot.

Carlson then turned to the Centers for Disease Control and Prevention’s latest public health guidance advising fully vaccinated Americans to continue taking precautions in public spaces.

"If the vaccine is effective, there is no reason for people who've received a vaccine to wear masks or avoid physical contact," he said. "So maybe it doesn't work, and they're simply not telling you that. Well, you'd hate to think that, especially if you've gotten two shots. But what's the other potential explanation? We can't think of one."

Carlson’s primetime show is among the most-watched cable news programs, and a video of his April 13 segment received nearly one million views on Facebook. 

The video was flagged as part of Facebook’s efforts to combat false news and misinformation on its News Feed. (Read more about our partnership with Facebook.) 

Asked about Carlson’s comments, Fauci told CNN that they were "certainly not helpful to the public health of this nation."

"That’s just a typical crazy conspiracy theory," Fauci said. "Why would we not tell people if it doesn't work? Look at the data. The data are overwhelming in the three vaccines that have been approved for use in an emergency use authorization, the J&J, the Pfizer, and the Moderna. You had 30,000, 44,000, and 40,000 people in the clinical trials, with an overwhelming signal of efficacy. So I don’t have any idea what he’s talking about."

COVID-19 vaccines are effective

The proof that the vaccines work includes a lengthy regulatory process and vaccine trials that happened around the world. 

The Food and Drug Administration has authorized for emergency use two-dose vaccines from Pfizer-BioNTech and Moderna, as well as a one single-dose vaccine from Johnson & Johnson. The three were approved after clinical trials involving tens of thousands of participants.

As of April 15, nearly 126 million Americans had received at least one dose of a vaccine, and over 78 million have been fully vaccinated, according to the CDC. The Pfizer and Moderna vaccines have accounted for the vast majority of those inoculations.

Clinical trials showed the Pfizer vaccine to be 95% effective at preventing COVID-19 infections, compared with 94% for Moderna and 66% for Johnson & Johnson, according to the CDC. The Johnson & Johnson vaccine was also found to be 85% protective against severe disease.

The clinical trials "clearly show the efficacy of each vaccine," said Richard Watanabe, professor of preventive medicine at the University of Southern California.

Some fully vaccinated people can still get infected, since no vaccine is 100% effective. But the clinical studies show the vaccine can keep them from getting seriously ill, the CDC says.

"It is incontrovertible that the vaccines work," said Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security. "Just look at hospitalization rates."

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Further studies have since supported the trial findings. A CDC study published March 29 found that under "real-world conditions," the Pfizer and Moderna vaccines were 90% effective against infections two weeks after the second dose and 80% effective 14 days after the first dose.

A separate study conducted in Israel and published Feb. 24 in the New England Journal of Medicine found that two doses of the Pfizer vaccine provided nearly 90% protection.

"Israel is a good example of what high population-level vaccination rates can achieve," said Brooke Nichols, assistant professor of global health at Boston University. "Once they achieved high vaccination coverage, cases began to plummet."

Explaining the guidance to continue wearing masks, social distancing

Carlson’s claim that "maybe (the COVID-19 vaccine) doesn’t work" hinged on the CDC’s latest guidance recommending that fully vaccinated Americans continue taking precautions in public.

Carlson said there are no good reasons for that. We found several, though.

The guidance reflects the fact that scientists are still learning about the vaccines: how long protection lasts; how much vaccines protect against emerging variants of the virus; and to what extent the vaccines prevent asymptomatic infections and transmission of the virus.

The CDC says preliminary evidence indicates that the vaccines "may provide some protection" against certain variants, and that "a growing body of evidence" suggests fully vaccinated people are less likely to be asymptomatic carriers of the virus and potentially less likely to pass it along to others. 

But the science on those questions is not settled, Watanabe said, and fears that newer variants could be more transmissible make additional safeguards important for now.

In public spaces, there is no way to tell who is among the roughly 25% of the U.S. population that has been fully vaccinated. Some "very vulnerable people" remain at risk, Nichols said. 

"Public health guidance on masks is not going to change until enough people are vaccinated because it is operationally very difficult to be able to tell who was vaccinated and who is not if you are, for example, working in a store," Adalja said.

Carlson past comments about the COVID-19 vaccines

Responding to Fauci’s criticism on his show April 14, Carlson claimed he had "never for a minute doubted" that the COVID-19 vaccines work, despite expressing that very doubt the night before, and saying there was no other plausible explanation for the CDC’s guidance

"Who is doubting that vaccines work? For the record, we never for a minute doubted it. We bought all of that stuff completely at face value. We believe in science," Carlson said, adding that he trusted the pharmaceutical companies behind the vaccines. "The only reason we are asking the question is because the people in charge are acting like it doesn't work."

A Fox News spokesperson cited those comments and other examples of Carlson claiming to support vaccines, including when he said he’s "not against it on principle" during his April 13 segment and when he said March 30, "I think of myself as pretty pro-vaccine myself." 

But Carlson has also questioned the vaccines and U.S. vaccination efforts before, just as he cast doubt previously on the effectiveness of masks and the threat of the coronavirus

On Feb. 9, Carlson said the government’s handling of the vaccines "did not inspire confidence" and that U.S. authorities were "lying" about their safety and effectiveness. On other occasions, he has suggested that the government is using the vaccines as a form of "social control" and that the shots would be made mandatory, which is not the case.

Many questions about the vaccines that Carlson has claimed authorities have "discouraged" Americans from asking have been answered by public health agencies and also by news outlets, including PolitiFact.

Our ruling

Carlson said, "Maybe (the COVID-19 vaccine) doesn't work, and they're simply not telling you that."

That claim is countered by clinical trials and real-world studies that show the available vaccines effectively protect against COVID-19 infections and severe symptoms. 

Carlson based his claim largely on the fact that the CDC still recommends that fully vaccinated people wear masks and keep their distance in public spaces. Carlson said he couldn’t think of a reason why the CDC would do that, but we found some pretty simple explanations.

Experts said those precautions are advisable because most of the U.S. population remains unprotected and because scientists are still studying to what extent the vaccines stop transmission, among other things.

We rate Carlson’s statement Pants on Fire!

Our Sources

Fox News, "Tucker Carlson Tonight," April 13, 2021

Fox News, "Tucker Carlson Tonight," April 14, 2021

U.S. Centers for Disease Control and Prevention, "COVID-19 Vaccinations in the United States," April 15, 2021

CrowdTangle, accessed April 14, 2021

CNN, "New Day," April 14, 2021

Yale Medicine, "Comparing the COVID-19 Vaccines: How Are They Different?" April 13, 2021

U.S. Centers for Disease Control and Prevention, "Key Things to Know About COVID-19 Vaccines," April 13, 2021

U.S. Centers for Disease Control and Prevention, "Different COVID-19 Vaccines," April 13, 2021

U.S. Centers for Disease Control and Prevention, "Johnson & Johnson’s Janssen COVID-19 Vaccine Overview and Safety," April 13, 2021

U.S. Centers for Disease Control and Prevention, "Benefits of Getting a COVID-19 Vaccine," April 12, 2021

U.S. Centers for Disease Control and Prevention, "COVID Data Tracker Weekly Review," April 9, 2021

U.S. Centers for Disease Control and Prevention, "Pfizer-BioNTech COVID-19 Vaccine Overview and Safety," April 5, 2021

U.S. Centers for Disease Control and Prevention, "Moderna COVID-19 Vaccine Overview and Safety," April 5, 2021

U.S. Centers for Disease Control and Prevention, "Ensuring COVID-19 Vaccines Work," April 5, 2021

U.S. Centers for Disease Control and Prevention, "Science Brief: Background Rationale and Evidence for Public Health Recommendations for Fully Vaccinated People," April 2, 2021

U.S. Centers for Disease Control and Prevention, "Interim Public Health Recommendations for Fully Vaccinated People," April 2, 2021

U.S. Centers for Disease Control and Prevention, "Interim Estimates of Vaccine Effectiveness of BNT162b2 and mRNA-1273 COVID-19 Vaccines in Preventing SARS-CoV-2 Infection Among Health Care Personnel, First Responders, and Other Essential and Frontline Workers — Eight U.S. Locations, December 2020–March 2021," April 2, 2021

U.S. Centers for Disease Control and Prevention, "CDC Real-World Study Confirms Protective Benefits of mRNA COVID-19 Vaccines," March 29, 2021

The New England Journal of Medicine, "BNT162b2 mRNA Covid-19 Vaccine in a Nationwide Mass Vaccination Setting," April 15, 2021

The Independent, "Tucker Carlson says US authorities ‘lying’ about Covid vaccines as conservative media sows doubts over safety," Feb. 10, 2021

STAT News, "BNT162b2 mRNA Covid-19 Vaccine in a Nationwide Mass Vaccination Setting," Feb. 2, 2021

The Daily Beast, "Tucker Carlson Tells His Giant Fox Audience Not to Trust COVID Vaccines," Jan. 19, 2021

PolitiFact, "Answering questions, concerns about the coronavirus vaccines," April 14, 2021

PolitiFact, "Ask PolitiFact: I got the Johnson & Johnson vaccine. Am I going to be OK?" April 13, 2021

PolitiFact, "No, it’s not safer to skip the COVID-19 vaccine to avoid permanent side effects," March 31, 2021

PolitiFact, "Ask PolitiFact: How can COVID vaccines be safe when they were developed so fast?" March 29, 2021

PolitiFact, "Yes, data shows COVID-19 vaccines are safe despite quick timeline," March 26, 2021

PolitiFact, "No, Biden didn’t promote ‘mandatory’ COVID-19 vaccines in primetime address," March 12, 2021

PolitiFact, "You’re fully vaccinated against COVID-19. What can you do now?" March 11, 2021

Statement from Fox News, April 14, 2021

Email interview with Brooke Nichols, assistant professor of global health at the Boston University School of Public Health, April 15, 2021

Email interview with Amesh Adalja, senior scholar at the Johns Hopkins University Center for Health Security, April 14, 2021

Email correspondence with Drew Weissman, professor of medicine at the University of Pennsylvania Perelman School of Medicine, April 14, 2021

Email interview with Richard Watanabe, professor of preventive medicine and associate dean for health and population science programs at the University of Southern California’s Keck School of Medicine, April 14, 2021

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Tucker Carlson falsely claims COVID-19 vaccines might not work

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