The president wants to show that he is activating the full power of the federal government in pushing for the health care system to react, treat and find a vaccine. But the infrastructure of vaccine development is not conducive to political pressure or a runaway pandemic.

And while no one is saying the current candidate vaccines are dangerous, they warrant dutiful examination “because in contrast to drugs, vaccines are given only to healthy people,” said Barry Bloom, a professor at the Harvard School of Public Health. “We have to be enormously careful not to harm anyone.”

If there are harms, he added, “the antivaxxers can set back not only this vaccine but all vaccines.”

A growing anti-vaccine movement contributed to the U.S. measles epidemic last year — the worst since 1992. Anti-vaxxers are already spreading conspiracy stories about the virus and predicting massive injuries from any vaccine, said Renée DiResta, who monitors such groups at the Stanford Internet Observatory.

Lives in the balance

Most people will be eager to get vaccinated if the coronavirus continues on its terrifying course. Experts say the vaccine types with the best chance of early approval seem safe, though none has been licensed for human use. If properly warned of possible side effects, people might accept them in exchange for a shot that keeps them from getting sick or spreading the disease.

Some even suggest it would be unethical not to accelerate the approval process at a time when the virus is killing thousands worldwide.

“The normal development of a vaccine is long and large and defensive because you’re developing something to be given to healthy people, most of whom will stay healthy and will never need the benefit of the vaccine,” said Michael Watson, who has developed vaccines for 25 years — including at Moderna, which is working on a vaccine with the NIH’s National Institute of Allergy and Infectious Diseases. “If you’re developing a cancer treatment, you can take quite a bit of risk for saving someone’s life. And the situation also changes when you’re in a global pandemic.”

Still, it’s unclear how fast is too fast.

Some scientists worry the Moderna vaccine could cause “immune enhancement,” a complicated reaction that makes a vaccinated person sicker when they catch the virus than if they hadn’t gotten the shot. NIAID said in a statement it was looking carefully for signs of this phenomenon in the Moderna trial. But agency scientists see little risk the experimental vaccine will cause the problem, it said.

The government may face its first big regulatory decision in about four months, when NIAID and Moderna turn over data on the safety and immunity of their vaccine, which they began testing on the first of 45 individuals in Seattle on Jan. 16.

The FDA would have the legal authority to promise emergency authorization of the Moderna vaccine based on a subsequent Phase II trial of a few hundred additional people. But that would be unheard of for a vaccine designed for massive use. Typically, such vaccines are tested on thousands in an area where there’s lots of disease, in order to directly measure how well the vaccine compares with a placebo. That process can take years.

On the fast track

The possibility that the FDA could preapprove widespread emergency use before the side effects are fully understood, along with Trump’s eagerness, worries some of the dozen vaccine experts interviewed by POLITICO.

“We seem to be willing to rush a vaccine into clinical trials without extensive animal model or safety testing,” said Paul Offit, a University of Pennsylvania immunologist who co-developed the rotavirus vaccine. “People are so scared of coronavirus that even those who are young and healthy will be willing to take a relatively untested product — even though the wild-type virus is unlikely to kill them.”

Offit’s vaccine, which eliminates thousands of infant deaths each year, took 26 years from design to licensure.

Red tape and delay can sometimes pay dividends in drug and vaccine approvals. Industry officials laid into FDA official Frances Kelsey in 1961 for her reluctance to approve their morning sickness drug thalidomide, but her sloth turned into a blessing. While Kelsey pondered the submission, news of crippling birth defects in thousands of babies poured in from Europe, and the FDA never approved the drug.

During the 2009 H1N1 swine flu pandemic, federal officials decided not to approve vaccines that contained a new substance designed to boost the vaccine’s effectiveness. As a result, the United States was spared a controversy over an unpredictable side effect — narcolepsy — that struck people in Finland who got the newer shots.

Some of the officials who made that decision had the 1976 swine flu fiasco on their mind. That year, after a new strain of influenza virus swept Fort Dix, N.J., the CDC became worried about similarities to the 1918 pandemic flu and convinced President Gerald Ford to order vaccines for the whole country. But the flu strain turned out to be relatively mild, and 450 people who’d received the vaccine got Guillain-Barré, a rare form of paralysis. Although later studies showed the vaccine was responsible for a minority of those cases, the debacle damaged trust in the government — and vaccination.