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Flaws in Covid vaccine safety system that could miss unexpected side effects, experts say


Rapid detection of an ultra-rare blood clotting reaction in some Covid-19 vaccinees has shown the power of a federal alert system for vaccine safety issues, but experts fear the program’s blind spots may interfere with the detection of other unexpected side effects.

Before the start of the pandemic, the Food and Drug Administration had scaled back a program it was using successfully to track adverse events during and after the 2009 H1N1 influenza pandemic, and the agency is still ramping up its replacement, said Dr Robert Chen, scientific director of the Brighton Collaboration, a global nonprofit vaccine safety network.

“It was pure bad luck that they were between the systems when Covid hit,” said Chen, who helped create America’s existing vaccine safety systems for nearly 30 years at the Centers for Disease Control and Prevention.

FDA officials acknowledged that some data analysis would not begin for weeks or months, but said the government was monitoring vaccine reactions with “state-of-the-art” systems.

“The FDA and CDC have strong safety and efficacy monitoring systems in place to monitor Covid-19 vaccines authorized for emergency use in the United States,” wrote Abby Capobianco, door – FDA speech, in an email.

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There is no doubt that the country’s vaccine surveillance system worked as expected this spring when it identified unusual cases of blood clots associated with low platelet counts in 15 people who had received the Covid-19 vaccine in one. Johnson & Johnson coup, said Dr. Jesse Goodman, a former chief scientist at the FDA. Three people died.

“The good news for a very rare event is that it will show up on VAERS,” Goodman said on a call with reporters, referring to the vaccine adverse event reporting system, jointly managed by the FDA and the CDC since 1990.

But other potentially dangerous and unforeseen reactions to vaccines may not be so evident in VAERS, a system that would miss many potential side effects – or in additional surveillance systems across the country, including the Vaccine Safety Datalink and the new tracking. by phone from CDC. program, v-safe.

“It’s all a mishmash of different data collection systems,” said Dr. Katherine Yih, biologist and epidemiologist specializing in vaccine surveillance at Harvard Pilgrim Health Care. “It’s worth saying that it’s not as good as it could be.”

The Vaccine Safety Datalink, while highly regarded, did not include enough vaccinations in its data from nine hospital systems covering 12 million people to catch the J&J problem, CDC officials said. And v-safe enrollment fell short of expectations, with around 6 million people enrolled at the end of March, just 6.4% of those who had been vaccinated by that time.

This means that at a time when roughly 100 million Americans have been fully vaccinated against Covid-19, the United States continues to rely on a patchwork network of vaccine surveillance systems that may fail to monitor some large enough population, experts told KHN. .

“I’m very concerned about this,” said Goodman, who also headed the FDA’s Biologics Assessment and Research Center, or CBER, and is now a professor of infectious diseases at Georgetown University. “I think we should see this report on all of these vaccines. Four months ago it was promised this was happening.

The three vaccines used in the United States – produced by Pfizer, Moderna and Johnson & Johnson – have been shown to be safe and effective in clinical trials on tens of thousands of volunteers.

But even the best trials aren’t big enough to capture all of the issues, especially the rarest ones, if they only occur in certain groups or outside of a certain time frame. It is important to monitor side effects after vaccines are distributed to the population – an effort known as pharmacovigilance – to ensure not only safety but also public confidence.

Vaccine safety experts have said they fear the FDA has downsized a system known as the Rapid Post-Licensing Immunization Safety Monitoring Network, or PRISM, long considered a monitoring tool.

“Before PRISM, I felt like we were sort of in the dark ages,” said Steve Anderson, director of the FDA’s Bureau of Biostatistics and Epidemiology, at a 2016 workshop. When PRISM came along, it really was a game-changer for us. ”

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PRISM linked four major health plans in different parts of the country with eight national immunization registers. During the H1N1 pandemic, it detected signals for three potentially vaccine-related adverse events and was used to rule out the two that were unrelated and the one, Guillain-Barré syndrome, that was.

The system included records of nearly 40 million people, said Daniel Salmon, former director of vaccine safety at the Office of the National Vaccine Program. Having a large number of records of people vaccinated “really boosts your ability to understand what’s going on,” he said.

PRISM, which was reused for drug safety, now contains data from around 60 million people, but it was not used to track vaccine reactions during the Covid-19 pandemic, said Salmon, who supervised the safety surveillance of the H1N1 vaccine.

“With PRISM, we tested it in a crisis and it worked for a decade,” he said. “I was really surprised not to use it for Covid-19. That’s why we built it.

A newer system, called the Biologics Efficacy and Safety System, or BEST, was launched in 2017, but only recently started monitoring data weekly for 15 predefined adverse events among Medicare beneficiaries. It will be expanded to include commercial databases from the end of June, according to Capobianco, the FDA spokesperson.

There is no single manager. You have to have someone in charge.

A search for possible cases of the rare disease linked to the J&J vaccine began in mid-April and will be expanded in the coming weeks, she added.

FDA officials said the capabilities of PRISM have been built into BEST, which can examine the data of 100 million people. Experts told KHN that it had not been widely used to monitor post-vaccination effects, but Capobianco said, “We disagree.”

“BEST is designed as a state-of-the-art active surveillance system,” she wrote.

The problem is that authorities have relied heavily on VAERS, a “passive” system that relies on reports from patients and healthcare providers to report post-vaccination issues that may or may not be vaccine-related. A robust “active” surveillance system can search large volumes of patient care records to compare rates of adverse events in people who have received vaccines with those who have not.

In addition, some vaccine safety experts report a lack of clear authority in this area. The Trump administration shut down the NVPO, a federal office specializing in vaccine safety oversight, merging it into a government agency focused on infectious diseases.

As a result, oversight of the safety of the Covid-19 vaccine is fragmented among federal agencies, said Salmon, who now heads the Institute for Vaccine Safety at the Johns Hopkins Bloomberg School of Public Health.

“There is no one responsible,” he said. “You must have someone in charge.”

Officials in the Biden administration praised the country’s vaccine surveillance system, noting that it had reported Johnson & Johnson’s problems in the weeks after the vaccine rolled out. Federal officials have suspended distribution to assess other cases and next steps. They were helped by the fact that European regulators found similar problems in another vaccine.

“VAERS worked exactly as expected in this case,” said Dr Tom Shimabukuro, head of the CDC’s Covid-19 vaccine task force.

That’s right, said Dr Steven Black, co-director of the Global Vaccine Data Network. Still, he noted, there is room for improvement, especially more funding and better collaboration.

“It’s a guarantee for our people,” Black said. “Whether it’s flu shots or Covid vaccines, you need to have a viable and strong system. Just because we think they are safe doesn’t mean you don’t need systems in place to back up that opinion. “

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