Why is it so hard to review the Johnson & Johnson vaccine? Data.


“We will never have perfect data, and there will always be uncertainty,” said Grace Lee, professor at Stanford University and chair of the committee’s COVID-19 vaccine safety technical subgroup. advisory, when the group met on Wednesday. “For me, it’s really about getting better risk estimates.”

Committee members agreed to meet again once they have had more time to collect and assess data on who may be most at risk for complications, and how that compares to the risk of catching it. and spread the covid.

All six cases reported after the vaccine became widely available were in women; an additional case – a man – has been reported during clinical trials. All of the patients were between 18 and 48 years old, and several were treated with the anticoagulant heparin, which is commonly used for clots, but which made these patients worse. The symptoms appear to be very similar to those associated with AstraZeneca’s anti-covid vaccine, which many European countries have limited or even stopped using. The active components of both are delivered to cells by adenoviruses that have been altered so that they cannot replicate.

But since there are other treatments available that use entirely different methods, experts say it’s a good idea to stand and see if more information becomes available. The Johnson & Johnson vaccine only counts 7.5 million of the 195 million American photographs delivered; Pfizer-BioNTech and Moderna, which use mRNA rather than adenoviruses, are responsible for the rest.

“We will never have perfect data and there will always be uncertainty. For me, it’s really about getting better risk estimates. ”

“The risks and benefits of continuing to administer the J&J vaccine cannot be considered in isolation,” says Seema Shah, bioethicist at Lurie Children’s Hospital in Chicago. “If people have alternatives, at least while the FDA is thinking, it makes sense to steer people toward those alternatives.”

However, the resumption of the Johnson & Johnson shots does not necessarily mean that they will be accessible to everyone. The safety of vaccines is important because they are given to healthy people, rather than treating people who are already sick, and successfully determining which groups might see the most benefit – or the most harm – could mean that the vaccines are US regulators will give recommendations at several levels. Several EU countries, for example, have said the AstraZeneca vaccine should be given to older people at higher risk of complications from covid, rather than younger people who may be at higher risk of vaccine complications.

“At the end of the day, the critical issue is if I’m a 30-year-old female and I get this vaccine, how much will it increase my risk for this bad thing?” says Arthur Reingold, chair of the California covid-19 scientific safety review task force and former member of the CDC’s vaccine advisory committee.

A more complicated question is what data the committee will look at to make a final decision.

No complete data

Information may be limited because the problem was detected early and because the Johnson & Johnson vaccine has so far only been deployed in the United States (the company has said it is delaying delivery to countries in the ‘European Union). American medical data is very fragmented.

Without a national health system, there is no comprehensive way to assess the risks and benefits for different groups who have received the vaccine. There is no routine federal capacity to link patient data to immunization records. Instead, regulators are hoping clinicians hear about the hiatus and proactively report cases they did not previously have linked to vaccinations.

“It might make a clinician say, ‘Oh my God, Mrs. Jones did this three weeks ago,’” says Reingold. Plus, he says, “there are still quite a few people who have received a dose in the past two weeks, and some of them might develop this rare side effect.”

The voluntary system may seem archaic, but this is how the six cases reviewed were brought to the attention of the authorities. They were reported to the CDC through an online database called the Vaccine Adverse Event Reporting System, or VAERS. It is an open website for doctors, patients and caregivers to inform the government about the potential side effects of vaccines.

Because the system is so open and requires opt-in participation, it is impossible to calculate exact risks using VAERS data. Epidemiologists typically see it as a place to look for hypotheses that link vaccines to side effects, rather than a source that can be used to confirm their suspicions.



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