The Trump administration wants to take credit for a covid vaccine. Trump supporters are undermining it.

Candace Owens, a prominent Black activist and Trump ally, tweeted on Dec. 9 that “the same people that are out here yelling ‘my body my choice’ will be telling you that the government has a right to force vaccinate you for a virus that has a 99% survival rate.” Twitter spokeswoman Lauren Alexander said the tweets did not violate the company’s misinformation rules, which specifically prohibit false statements saying the vaccine could be used to harm or control populations.

Complicating matters is Trump himself. The president — who has a history of questioning vaccines — has also been notably less vocal about vaccine promotion. He has hailed his administration’s investments in vaccine development, including tweeting that the vaccine’s impending arrival was “GREAT NEWS” — but has not committed to taking it publicly. Since the election, he has used his Twitter account to primarily focus on baseless claims of election fraud rather than the covid crisis.

Trump’s messaging that people should distrust authority has made it harder for the administration to take a victory lap over vaccine development, misinformation experts said.

“His base has been primed to believe conspiracies and disbelieve in official accounts,” said Joan Donovan, a disinformation expert who is director of the Technology and Social Change Research Project at the Shorenstein Center on Media, Politics and Public Policy at Harvard University. “The skepticism that allows him to draw in these communities is the same skepticism that they are bringing to this world historic moment.”

“In close consultation with local, national and global public health authorities around the world, we are focused on removing misleading information that presents the biggest potential harm to people’s health and well-being,” Twitter’s Alexander said. “Starting in early 2021, we may label or place a warning on Tweets that advance unsubstantiated rumors, disputed claims, as well as incomplete or out-of-context information about vaccines.”

“President Trump has repeatedly referred to the vaccines as ‘miracles’ and encouraged the American people to take them — including when he hosted an hours-long, live-streamed and nationally televised summit to educate the American people about the vaccine development and distribution process, build confidence in the safety and efficacy of the vaccines, and commemorate their creation as a national achievement that will save millions of lives,” said White House spokesman Brian Morgenstern.

Facebook didn’t respond to requests for comment.

In recent years, conspiracies and misleading narratives have moved from the fringes to the center of the national conversation — thanks, in no small part, to a disinformation machine led by Trump, high-profile influencers, and his most ardent supporters. Trump has retweeted supporters of the conspiracy theory QAnon hundreds of times, raised misleading claims about mail-in voting and election results, and even suggested that injecting disinfectant could help cure the virus. Disinformation experts called the campaign by Trump and his influencers the most significant threat to democratic processes during the presidential election — worse, even, than Russian interference.

The distrust of authority dovetails with a year-long push by activists that have effectively used social media to undermine vaccination. In the spring, for example, online anti-vaccination groups came together with groups supporting Trump and the conspiracy theory QAnon to push a viral video that made false claims about the virus, such as wearing a mask makes it easier to contract covid-19, according to researchers.

Experts say it is unlikely that the federal government could force people to take a vaccine. Both president-elect Joe Biden and Dr. Anthony S. Fauci have said it will not happen.

However, in recent segments on Fox, host and Trump ally Tucker Carlson has warned that a vaccine will be mandated by government, and has highlighted stories of vaccine side effects. He has also blamed Twitter for “censoring” people who criticize the vaccine as “social control.”

In a show referencing a New York lawmaker’s bill to mandate vaccination, he said, “They are planning to force you to take the coronavirus vaccine. It’s so safe, they have to threaten you to take it.”

On Twitter earlier this month, Powell pushed theories that “big government” would conduct surveillance of people who refused vaccination, which she likened to “authoritarian communist control straight from #China.” Twitter said Powell’s tweet didn’t violate its policies.

Trump promoted anti-vaccine conspiracy theories before taking office, and even at one time reportedly proposed known vaccine skeptic Robert Kennedy Jr. to lead a commission on vaccine safety. During his presidency, Trump would bring up vaccines with advisers, such as former FDA Commissioner Scott Gottlieb, and whether they were really safe, current and former administration officials said.

Some of the conspiracies circulating about the vaccine are similar to misleading narratives that Trump pushed or alluded to about the virus itself. For instance, throughout the pandemic Trump called covid-19 the “China virus” and used anti-China rhetoric when describing it.

Now the anti-China rhetoric is being deployed by Trump allies to question the vaccine. This month Fox News commentator and Trump ally Laura Ingraham posted a story on Facebook from the right-leaning tabloid the Daily Mail that purported to show documents claiming that Chinese Community Party loyalists worked at pharmaceutical companies that developed the coronavirus vaccine.

A correspondent for the Trump-friendly news channel NewsMax also cited the Daily Mail article to amplify unsubstantiated allegations that the Chinese Communist Party was linked to vaccines this month as well.

Conspiracy theories about the vaccine are also brewing within Trump’s base, particularly among Evangelical Christians and followers of the QAnon conspiracy theory, according to a new report by the misinformation research group Zignal Labs.

Zignal noted that some of the same people sharing the conspiracies about the vaccine, such as Powell, were also proponents of conspiracies around the results of the presidential election.

Zignal found that the most popular misleading story line about the coronavirus vaccine in recent weeks was about people who took the Pfizer vaccine developing the disease Bell’s palsy, which temporarily paralyzes muscles in the face. An article from the Daily Mail, which reported that four volunteers who took the vaccine then developed the disease, garnered more than 179,000 shares on Facebook and 12,000 shares on Twitter, with an evangelical Christian community on Facebook contributing the single largest number of shares.

Fact-checking group PolitiFact has said that the Bell’s palsy story has been exaggerated and distorted by social media users. While the original Daily Mail story was accurate, and therefore allowed by the social media companies, scientists have said that the number of people who developed Bell’s palsy — 4 in a group of 22,000 — is consistent with the number of people who have the disease in the actual population, and may have nothing to do with the vaccine, the fact-checking group said. The FDA is monitoring the issue. At the same time, a popular Facebook meme appearing to depict the volunteers was actually recycling a photo from 2019.

Trump himself has been somewhat absent from the conversation, frustrating aides who say that he could have a major impact on drumming up support for vaccination, say people familiar with the discussions who spoke on the condition of anonymity to discuss sensitive matters freely.

With so many Americans expressing doubt about the vaccine, aides say that he could convince tens of million of Americans — his most fervent supporters — that it was safe if he took it himself, the people said. But so far, he has not publicly announced plans to do so and has not held any major event to promote it. He has tweeted praising the vaccine, but has eschewed any public appearances since its release to either take it or laud it, instead spending much of his time in meetings and on phone calls about overturning the election, aides said.

Surgeon General Jerome Adams, Defense Secretary Christopher Miller, and Fauci from the National Institutes of Health have all had on-camera vaccines, while a number of administration officials have gotten it privately, the people said.

At a news conference last week, White House press secretary Kayleigh McEnany said that Trump would take the vaccine “as soon as his medical team determines it’s best.” She described the administration’s efforts to produce a coronavirus vaccine as “historic investments” that “will mark the beginning of the end of the pandemic.”