For years, Donald Trump has been among the most prominent anti-vaccination voices in the US, repeatedly blaming childhood immunisations for causing what he described as an autism “epidemic”.
Now, faced with a real epidemic that threatens his re-election bid, the president has become a cheerleader for a quick Covid-19 vaccine, which might allow him to claim he has turned the tide against the virus if it is authorised for use before polling day.
The real anti-vaxxer threat now comes from the Democrats, according to Mr Trump, who this week accused his rival Joe Biden of peddling “reckless anti-vaccine rhetoric”.
“They are talking about endangering lives, and it undermines science,” the president said on Monday, after Mr Biden and his running mate Kamala Harris both warned about the safety implications of rushing out a vaccine for political gain.
Last weekend, Ms Harris responded to a question on whether she would take a vaccine that was distributed ahead of the election by saying she “would not trust Donald Trump”.
“It would have to be a credible source of information that talks about the efficacy and the reliability of whatever he’s talking about,” Ms Harris told CNN. “I will not take his word for it.”
Experts worry that comments like this from Democratic politicians, who have tended to draw support from people who are more pro-vaccination, could pose just as big a risk to public confidence in immunisations as Mr Trump’s apparent haste.
“I have seen the way these theories work, what provokes fires and what does not,” said Heidi Larson, director of the vaccine confidence project at the London School of Hygiene and Tropical Medicine. “[Biden and Harris] are throwing fuel on this one.”
She added: “One of the things that is going to affect confidence is that there is so much political back and forth. When people in authority seem confused, or are contradicting each other, that is not a good thing.”
Signs exist that the rancorous debate over vaccines is starting to affect public opinion. A poll released this week by the Kaiser Family Foundation think-tank found that more than 50 per cent of Americans would not want to receive a vaccine if it were authorised for use before the election. Coronavirus is now the second most important election issue after the economy, the poll found.
Jerome Adams, the Trump-appointed Surgeon General, sounded the alarm this week. “We have a once in a century global pandemic superimposed on top of a presidential election,” he warned the Senate health committee. “That has made messaging even more difficult and concerning.”
Mr Trump has said he thinks a vaccine will be ready by the end of the year, and perhaps even next month. His administration has considered granting emergency authorisation to a vaccine being developed by AstraZeneca, although the pharma company this week halted trials following a suspected serious adverse event in a study participant.
Stephen Hahn, the head of the US Food and Drug Administration, recently told the Financial Times he was willing to grant emergency approval to a vaccine even before the end of phase 3 clinical trials.
Mr Trump is a late convert to the pro-vaccine cause. For years, the president gave oxygen to the discredited theory that vaccines might cause autism, telling the South Florida Sun-Sentinel newspaper in 2007 that he thought giving children “massive injections at one time” had led to an autism “epidemic”.
Just before Mr Trump’s inauguration in 2017, Robert Kennedy Jr, the prominent anti-vaccination campaigner, said the president-elect had asked him to chair a committee on vaccine safety, although the appointment was never made.
Supporters say Mr Trump’s change of tone has not been prompted by the election, pointing out that he also called for parents to vaccinate their children last summer as measles outbreaks ripped through the US.
Despite Mr Trump’s conversion, vaccine hesitancy remains far more prevalent on the right, with 60 per cent of Republicans saying they would not want to take a pre-election Covid vaccine, compared with 46 per cent of Democrats, according to the KFF poll.
Rising public concern over vaccines is worrying not only public health experts but also the drug companies that make them.
This week, nine vaccine makers issued a rare joint statement committing to FDA guidelines and pledging not to submit a vaccine for approval before it is ready.
Large pharmaceutical companies with a major interest in vaccines pushed for the joint statement because they were worried that smaller drugmakers could be rushed into submitting a vaccine for approval, said one person familiar with the matter.
The person said the “misstatements and incompetence” by the politically appointed heads of the FDA and the Centers for Disease Control and Prevention made them concerned about losing the trust that is required for a successful vaccine to be a “public health game changer”.
And it is not just political outsiders who worry that politics and vaccine development might be a toxic mix: some of the most senior government scientists have similar concerns.
Speaking at this week’s Senate hearing, Francis Collins, the head of the US National Institutes of Health, said: “I hope that Americans will choose to take the information they need from scientists and physicians, not from politicians.”
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