The president’s top pandemic adviser also warned that rushing out one vaccine candidate could harm the progress of other vaccines. A number of firms now have potential vaccines in late-stage trials.
Dr Fauci’s comments came a day after reports emerged suggesting that the Trump administration was looking at emergency use authorisation (EUA) for a vaccine being developed by AstraZeneca and Oxford University.
The White House did not immediately respond to an Independent request for comment on the claims; a spokesperson for AstraZeneca denied the company had spoken with Washington officials.
“The one thing that you would not want to see with a vaccine is getting an EUA before you have a signal of efficacy,” Dr Fauci told the Reuters news agency on Monday.
“One of the potential dangers if you prematurely let a vaccine out is that it would make it difficult, if not impossible, for the other vaccines to enrol people in their trial,” he added.
Large-scale clinical trials of the leading vaccine candidates from Moderna Inc, Pfizer Inc and AstraZeneca Plc, which aim to enrol tens of thousands of volunteers, were launched in recent weeks. Johnson & Johnson last week said it hopes to include 60,000 subjects in its phase three vaccine trial.
On Sunday, the Trump administration hailed the Food and Drug Administration (FDA) emergency approval of a coronavirus treatment that uses plasma from recovered patients, a day after accusing the agency of impeding the rollout of vaccines and therapeutics for political reasons.
The FDA, explaining its decision, cited early evidence suggesting blood plasma can decrease mortality and improve the health of patients when administered in the first three days of their hospitalisation.
But some experts – including Dr Fauci – said there is not sufficient evidence to say that the plasma treatment is effective.
Michael Steele, who served as chair of the Republican National Committee from 2009 to 2011, said the Trump administration was putting politics ahead of science. “This is not about good science or even your health, it’s about his re-election,” he wrote on Twitter.
Safe and effective vaccines are seen as essential to ending the pandemic that has claimed the lives of more than 800,000 people worldwide, over 177,000 of them in the US.
Vaccine experts, however, worry that the White House may apply pressure on the FDA to push out a vaccine via an EUA before it has been fully tested – a pathway that has never been used to approve a vaccine intended for widespread use.
“I would be very worried about using an EUA mechanism for something like a vaccine. It’s very different from plasma therapy,” said Dr Peter Hotez, an infectious disease expert and vaccine researcher at Baylor College of Medicine.
Dr Fauci said the FDA’s guidance on vaccines – both for full approval and for an EUA – explicitly requires a demonstration that it is both safe and effective.
An EUA is typically used for products to “diagnose, prevent and treat serious or life-threatening diseases where the known benefits outweigh the potential risks of the product,” he added.
An EUA might be appropriate once studies have shown safety and effectiveness, but before the FDA has completed its formal review of the company’s marketing application, he said.
“To me, it’s absolutely paramount that you definitively show that a vaccine is safe and effective, both,” Dr Fauci said. “We would hope that nothing interferes with the full demonstration that a vaccine is safe and effective.”
With less than two months to go to the presidential election, Mr Trump – who is trailing Democratic candidate Joe Biden in most major polls – will be hoping for a coronavirus vaccine sooner, rather than later.
The strength of the economy had been the foundation of Mr Trump’s re-election campaign until coronavirus struck. But high unemployment figures and shrinking GDP have forced the Trump campaign to change tack, with the president playing on widespread social unrest to rally his base, and launching personal attacks on Mr Biden and his running mate, Kamala Harris.
But Mr Trump’s attacks on Mr Biden appear not to have cut through, with the Democratic candidate being praised by Fox News for his powerful speech at the party’s convention last week.
Some analysts and political commentators have said that a recovering economy could be Mr Trump’s only path to victory in November. But the president faces a huge challenge on that front, with large numbers of coronavirus cases and deaths still being reported across swathes of the country, raising the possibility of further lockdowns.
Additional reporting by agencies
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