SciTech

Johnson & Johnson vaccine recap

If you've heard anything at all about COVID-19 vaccines lately, you probably know that distribution of the Johnson & Johnson (J&J) vaccine was paused after six women developed blood clots, and one of them died. After evaluating that the risk of developing these blood clots is very low, the FDA recommended resuming J&J vaccine distribution after April 23 for individuals 18 and older. Here's a quick summary of what you need to know:

Should I be worried about getting blood clots from the J&J vaccine?

No, as the chances are about one in a million. However, women from 18 to 49 years of age should still be aware that there is a chance of developing these blood clots.

If you received the vaccine, you can look for symptoms of blood clots such as severe headaches and shortness of breath. A more detailed list of symptoms can be found on the CDC website. However, if it has been more than three weeks since you got the vaccine, it is not likely that you will develop these blood clots.

What are these blood clots, and what's causing them?

Blood clots are caused by platelets in the bloodstream. Platelets help stop blood from flowing out of wounds and form scabs to prevent excess blood loss. However, too many platelets can form blood clots inside the body. This means that instead of preventing blood from flowing out of the body, it can prevent blood from flowing around the body, which causes many problems.

The blood clots seen in patients who developed it after the J&J vaccine are unusual, however. Even patients with histories of low platelet counts developed blood clots in places such as the brain, lungs, and abdomen.

Scientists are currently unsure of what is causing these blood clots, but they believe it is related to an antibody released in response to a platelet formation factor.

What is the difference between the J&J vaccine and other vaccines?

The main difference is that the Pfizer and Moderna vaccines use messenger RNA (mRNA). These mRNAs tell cells how to make the protein unique to COVID-19, and the proteins trigger the immune system to create antibodies to fight COVID-19. The Johnson & Johnson vaccine (as well as the AstraZeneca vaccine) uses a more conventional approach of sending in a weak virus with the SARS-CoV protein to trigger an individual's immune response.