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Why the push for a quick coronavirus vaccine could backfire

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.

To be sure, this is not 1976.

“The first and most obvious difference is, in 1976 we never had a disease. We know this is a dangerous virus — that’s a day and night difference,” said Harvey Fineberg, chair of the National Academies’ Standing Committee on Emerging Infectious Diseases.

“There are two dangers of history: Failing to learn the lesson, and overlearning the lesson,” said Fineberg, who co-authored the definitive study of the swine flu affair. The best approach, he said, was to “think one step beyond the next step, and decide what you need to decide when you need to decide it.”

At a World Health Organization meeting Friday, the agency offered help to standardize tests and procedures for about 20 other target vaccines, said a scientist who attended the meeting by phone. Chinese military scientists are already testing their own coronavirus vaccine.

“The range of approaches on the table is amazing in a positive way,” said vaccine developer Stanley Plotkin, an emeritus professor at the Wistar Institute in Philadelphia. “I’m optimistic that probably more than one of those approaches will work.”

Plotkin’s rubella vaccine, which has prevented hundreds of thousands of cases of serious birth defects, is part of the MMR shot. It took six years to develop.

Source: politico.com
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