Posts mislead on Pfizer COVID vaccine’s impact on transmission

CLAIM: Pfizer admitted to the European Parliament that it had not tested the ability of its COVID-19 vaccine to prevent transmission of the virus before it entered the market, proving the company lied about this earlier in the pandemic.

AP’S ASSESSMENT: Missing context. Janine Small, president of international markets at Pfizer, told the European Parliament on Monday that Pfizer did not know whether its COVID-19 vaccine prevented transmission of the virus before it entered the market in December 2020. But Pfizer never claimed to have studied the issue before the vaccine’s market release.

THE FACTS: After Small testified before the European Parliament’s Special Committee on the COVID-19 Pandemic, misleading claims about whether Pfizer knew the impact of its COVID-19 vaccine on preventing transmission spread widely on social media.

Rob Roos, a Dutch European Parliament member who asked Small a question about transmission at the hearing, tweeted: “BREAKING: In COVID hearing, #Pfizer director admits: #vaccine was never tested on preventing transmission. ‘Get vaccinated for others’ was always a lie. The only purpose of the #COVID passport: forcing people to get vaccinated. The world needs to know. Share this video!”

The tweet, which included a video showing the exchange between Roos and Small, had received more than 232,000 likes and more than 166,000 shares by Thursday.

Other social media posts about the hearing used the hashtag #PfizerLiedPeopleDied.

At the hearing, Roos asked Small whether Pfizer had tested its COVID-19 vaccine for its ability to prevent transmission of the virus prior to its market release. Small answered: “No. We had to really move at the speed of science to really understand what is taking place in the market.” She went on to explain why Pfizer moved quickly to develop a COVID-19 vaccine as the virus spread worldwide.

While Roos and many others framed this as a new revelation, Pfizer never claimed that its clinical trial, upon which the vaccine was authorized for use, evaluated the shot’s effect on transmission. In fact, shortly before the vaccine’s release, the company’s CEO emphasized that this was still being evaluated.

A study funded by Pfizer and German vaccine maker BioNTech published in the New England Journal of Medicine on Dec. 10, 2020, a day before the Food and Drug Administration gave Pfizer’s COVID-19 vaccine emergency use authorization, did not include data about the vaccine’s effectiveness at reducing transmission of the virus.

Instead, it reported that two doses of the vaccine provided 95% protection against contracting symptomatic COVID-19 in people 16 and older. Pfizer CEO Albert Bourla also said in a December 2020 interview with NBC News that it was still unclear whether vaccinated individuals could carry the virus and transmit it to others.

“I think this is something that needs to be examined,” he told the network. “We are not certain about that right now.”

The FDA stated in a Dec. 11, 2020, press release announcing the authorization of Pfizer’s COVID-19 vaccine that “at this time, data are not available to make a determination about how long the vaccine will provide protection, nor is there evidence that the vaccine prevents transmission of SARS-CoV-2 from person to person.”

A Pfizer spokesperson told The Associated Press that its clinical trial was designed to evaluate the efficacy of its COVID-19 vaccine in preventing disease caused by the COVID-19 virus, including severe illness.

“Stopping transmission was not a study endpoint,” the spokesperson wrote in an email.

Asked for comment, Roos told the AP that he was not making a point about Pfizer, but about government mandates for the COVID-19 vaccines.

“I take fundamental rights seriously,” Roos wrote in an email. “For governments to infringe on them, they need a massive amount of evidence to prove the necessity. In this case, it was not even a part of the Pfizer trials.” He said that such mandates were based on “no evidence.”

But experts and research say that the COVID-19 vaccines have provided benefits in terms of limiting infections and transmission, at least with earlier variants of the virus and for a period of time after being vaccinated.

Dr. Walter Orenstein, associate director of the vaccine center at Emory University, told the AP that the fact that Pfizer did not address the vaccine’s impact on transmission during clinical trials is not unusual, because transmission is a complex metric to measure.

“It’s much more difficult to evaluate impact on transmission,” Orenstein, a professor of infectious diseases at the Emory School of Medicine, wrote in an email. “What is usually done is a randomized placebo controlled study, in which the recipients are ‘blinded (i.e., do not know whether they received placebo or vaccine.’”

Public officials have suggested on multiple occasions that COVID-19 vaccines prevent transmission, but that’s an overstatement. For example, in an October 2021 speech in Illinois, President Joe Biden said: “We’re making sure healthcare workers are vaccinated, because if you seek care at a healthcare facility, you should have the certainty that…the people providing that care are protected from COVID and cannot spread it to you. ”

While the vaccines do not eliminate all transmission, they can help. Studies done after distribution of the COVID-19 vaccines began, including research by Pfizer, did find that the company’s shot reduced asymptomatic infections in addition to symptomatic cases with earlier variants of the virus. Researchers in the United Kingdom reported in a February observational study that Pfizer’s vaccine helped cut transmission of the alpha and delta variants.

“Our study from earlier in the year shows that the Pfizer vaccine reduces transmission from people with breakthrough infections, at least in the 3 months post vaccine which we studied,” Dr. David Eyre, a professor of infectious diseases at the University of Oxford and lead author of the study, wrote in an email.

Experts have told the AP that while the original COVID-19 vaccines provide less protection against infection with the highly contagious omicron variant, they still protect against serious outcomes.

The CDC stated in an August report that receiving only the first one or two doses of a COVID-19 vaccine “provides minimal protection against infection and transmission” and that being up to date on all recommended booster doses “provides a transient period of increased protection against infection and transmission after the most recent dose, although protection can wane over time.”

Dr. Paul Offit, a member of the FDA’s Vaccines and Related Biological Products Advisory Committee, explained that while the vaccines do provide neutralizing antibodies, which help protect against infection, those kinds of antibodies quickly wane — even as protection against serious illness continues to last.

“It is fair to say that when you get a vaccine that clearly decreases your chance of getting infected, it does,” said Offit, who is also the director of the Vaccine Education Center at the Children’s Hospital of Philadelphia. “And therefore it decreases your chance of spreading it to others. But it’s not in any way absolute.”

Offit added that messaging to the public around the vaccines early on was flawed and should have been focused on their core benefit — preventing serious illness and hospitalization — since many would later cast doubt on the vaccines’ success because of “breakthrough infections.”

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This is part of AP’s effort to address widely shared misinformation, including work with outside companies and organizations to add factual context to misleading content that is circulating online. Learn more about fact-checking at AP.