By JoNel Aleccia, Kaiser Health News
Monday, May 3, 2021 (Kaiser News) – The rapid detection of an extremely rare blood clotting reaction in some recipients of Covid-19 vaccines demonstrated the effectiveness of a federal warning system for vaccine safety issues. However, experts fear that blind spots will appear in the program, which may hamper the detection of other unexpected side effects.
Before the pandemic began, the Food and Drug Administration had scaled back a program it used to successfully track adverse events during and after the 2009 H1N1 influenza pandemic, and the agency is still expanding its replacements, said Dr. Robert Chen, Scientific Director of the Brighton Collaboration, a not-for-profit global vaccine safety network.
“It is unfortunate that they were between systems when Covid was hit,” said Chen, who spent nearly 30 years helping the Centers for Disease Control and Prevention build existing US immunization safety systems.
FDA officials admitted some data analysis would take weeks or months to begin, but said the government is looking for vaccine responses with “state-of-the-art” systems.
“The FDA and CDC have robust safety and efficacy monitoring systems in place to monitor COVID-19 vaccines approved for use in the US emergency,” wrote Abby Capobianco, FDA spokeswoman, in an email.
No question about it, the country’s vaccine monitoring system ran as expected in the spring when it identified unusual cases of blood clots combined with low platelet counts in 15 people who had received Johnson & Johnson’s one-off Covid vaccine, 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 shows up at VAERS,” Goodman said on a call with reporters, referring to the Vaccine Adverse Event Reporting System operated jointly by the FDA and the CDC since 1990.
Other potentially dangerous, unexpected reactions to vaccines may not be as evident on VAERS, a system that is believed to miss many potential side effects, or the country’s additional monitoring systems, including the Vaccine Safety Datalink and the CDC’s new phone-based tracking , v-sure.
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“It’s a mess of different data collection systems,” said Dr. Katherine Yih, a biologist and epidemiologist who specializes in vaccine surveillance at Harvard Pilgrim Health Care. “It’s worth noting that it’s not as good as it could be.”
The vaccination safety data link, while highly regarded, did not include enough vaccinations in its data from nine hospital systems covering 12 million people to solve the J&J problem, CDC officials said. The enrollment in v-safe was less than expected. By the end of March, around 6 million people were enrolled, only 6.4% of those vaccinated at the time.
That means, at a time when around 100 million Americans have been fully vaccinated against Covid, the US continues to rely on a patchwork network of vaccine monitoring systems that may not be able to monitor a sufficiently large segment of the population to so experts told KHN.
“I’m very concerned about this,” said Goodman, who also directed the FDA’s Center for Biologics Evaluation and Research (CBER) and is now a professor of infectious diseases at Georgetown University. “I think we should see this coverage of all of these vaccines. It was promised four months ago that it would happen. “
The three vaccines used in the United States – manufactured by Pfizer, Moderna, and Johnson & Johnson – have been shown to be safe and effective in clinical trials involving tens of thousands of volunteers.
But even the best studies are not big enough to cover all problems, especially rare ones if they happen only in certain groups or outside of a certain time frame. It is important to track the side effects once the vaccines are distributed among the population – a measure known as pharmacovigilance – to ensure not only safety but also public confidence.
Vaccination safety experts have expressed concern that the FDA has scaled back a system known as the Rapid Immunization Safety Monitoring Network (PRISM), which has long been viewed as the workhorse of surveillance.
“Before PRISM, I felt like we were in the dark age,” said Steve Anderson, director of the FDA’s Biostatistics and Epidemiology, at a 2016 workshop. “When PRISM first came out, it really was one for us Game changer. “
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PRISM linked four major health plans in different parts of the country to eight state vaccination registers. Signals for three adverse events possibly related to the vaccines were detected during the H1N1 pandemic and it was used to rule out the two unrelated and Guillain-Barré syndrome.
The system contained records of nearly 40 million people, said Daniel Salmon, a former director of vaccination safety at the National Vaccine Program Office. Having a large number of records on people who have been vaccinated “really enhances your ability to figure out what’s going on,” he said.
Repurposed for drug safety, PRISM now contains data on approximately 60 million people, but was not used to track vaccine responses during the Covid pandemic, said Salmon, who oversaw safety oversight for the H1N1 vaccine.
“With PRISM, we tested it in a crisis and it worked for a decade,” he said. “I was really surprised when it wasn’t used on Covid. That’s why we built it. “
A newer system called the Biologics Effectiveness and Safety System (BEST) was launched in 2017, but has only recently started monitoring data for 15 predefined adverse events in Medicare recipients on a weekly basis. According to Capobianco, spokesman for the FDA, it will be expanded to include commercial databases from the end of June.
The search for possible cases of the rare disease related to the J&J vaccine began in mid-April and will expand over the next few weeks, she added.
FDA officials said PRISM’s capabilities have been built into BEST, which can examine data from 100 million people. Experts told KHN that it hasn’t been used extensively to monitor post-vaccination effects, but Capobianco said, “We disagree.”
“BEST was built to be a state-of-the-art active surveillance system,” she wrote.
The concern is that officials have relied heavily on VAERS, a “passive” system that relies on reports from patients and health care providers to flag post-vaccination issues that may or may not be related to the gunfire. A robust “active” monitoring system can search large volumes of patient records to compare the incidence of adverse events in people who have received vaccines with those who have not.
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In addition, some vaccination safety experts point to a lack of clear authority in this area. The Trump administration has shut down the NVPO, a federal agency with expertise in overseeing vaccine safety, and merged it into a government agency focused on infectious diseases.
As a result, oversight of Covid vaccine safety has been fragmented among federal agencies, said Salmon, who now heads the Institute of Vaccine Safety at the Johns Hopkins Bloomberg School of Public Health.
“There is not a single responsible person,” he said. “You must have someone in charge.”
Biden administration officials have praised the country’s vaccine monitoring system, indicating that it reported the Johnson & Johnson issues within weeks of the vaccine’s launch. Federal officials paused the distribution to assess additional cases and what to do next. (They were helped by the fact that European regulators had found similar problems with another vaccine.)
“In this case, VAERS performed exactly as intended,” 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. Nevertheless, there is room for improvement, especially for more resources and better cooperation.
“This is a protection for our people,” said Black. “Whether it’s flu vaccines or Covid vaccines, you need to have a stable and strong system in place. Just because we believe they are safe doesn’t mean you don’t need systems to support that opinion. “
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