A: Johnson & Johnson was granted emergency authorization use (EAU) by the FDA for a vaccine against COVID-19 in late February.
After receiving reports of a rare life-threatening blood clot condition occurring primarily in women under 50 within three weeks of getting this vaccine, CDC paused the use of the vaccine for 10 days. A few days ago, the CDC and FDA lifted the pause and required the manufacturer to add a warning label to the product.
The J&J vaccine became the third to be authorized in the battle against COVID-19. It uses a disabled non-coronavirus agent to convince the body to fight against the virus causing COVID-19. The advantages for this adenovirus vaccine is that refrigeration is not an issue as it is with mRNA vaccines produced by Pfizer and Moderna. Unlike the mRNA vaccines it requires a single injection. And it is very effective at preventing severe COVID-19, including against some of the new emerging variants.
Why was the use of J&J vaccine paused? To-date, there have been 15 reports of blood clots with 10 more under investigation. Except for one young man reporting similar symptoms during the clinical trials, all the reports so far have been in women under 50. This was enough for the CDC to call for a pause until they reviewed the situation.
Why was the pause lifted? The Advisory Committee on Immunization Practices (ACIP) advised the CDC to resume use of the J&J vaccine with a vote of 10-4. The CDC reported their reasons for lifting the pause in a joint press conference with the FDA. They expanded the definition of blood clots to avoid missing any additional cases and reviewed the safety monitoring systems for more case reports. As a result, they found a likely association between the J&J vaccine and these unusual blood clots. They determined that the benefits of vaccine outweighed the slight risk of the blood clots.
Four of the people on the advisory committee disagreed with this decision, and some other commenters thought it would have been better to limit the vaccine to older people or by gender. Why do some in the medical and scientific community disagree with the decision? Some think that changing the labeling as suggested by the CDC is not enough. Because there are other options for vaccination and the rate of COVID-19 cases occurring are declining, some are skeptical of continuing the use of the J&J vaccine in all adults in light of these risks.
In a commentary in the New England Journal of Medicine, Dr. Paul Sax recently outlined his concerns with this decision. He argues that for women under age 50, the risk of this rare blood clot—small as it is—is unnecessary. Other vaccines are widely available, so why take a known risk? “While the odds are overwhelmingly in [a younger woman’s] favor that everything will be fine, in practice, this would be giving a vaccine with a recognized safety issue when two highly effective and safe alternatives exists.”
As for adding a warning on the label as a solution, Dr. Sax says “I worry about women who lack the medical literacy to fully understand it, or the cultural authority to question what is being offered to them, or the forthrightness to request alternatives — or all of the above. And that can’t be right.”
Here’s where the scientists agree:
These are not your typical blood clots. thrombosis with thrombocytopenia syndrome (TTS) are not average blood clots. They occur with low platelets and other platelet abnormalities. The usual treatment for these blood clots (heparin) will make the clots worse.
The cases are very serious. These clots, unlike venous thrombosis, occur in extraordinary sensitive regions of the brain. As a result, they can cause critical illness and even death.
They are rare. There has been 1 case per 500,000 people vaccinated reported. The chance of getting TTS after and adenovirus vaccination is the same as the risk of being struck by lightening in a single year.
The risk is higher in younger women. Women ages 18-49 have a risk of developing TTS of 1 per 140,000 doses of vaccine.
They occurred shortly after the vaccine. Symptoms were reported 6-15 days after vaccination. The average was 8 days.
Similar cases of blood clots have occurred with another adenovirus vaccine, the Astra-Zeneca vaccine being used in other countries. There have been no similar events with the mRNA vaccines made by Pfizer and Moderna.
The same CDC advisory committee has another meeting on May 5th. The public is invited to attend as they discuss the safety of vaccinations in the US. Details are available here.