Thrombosis with thrombocytopenia syndrome, or TTS, has been reported as a possible but rare side effect of the Johnson & Johnson vaccine in particular. As of March 18, 2022, there have been 60 confirmed reports of TTS, 9 of which were fatal, out of the 18.5 million doses of the J&J vaccine.

For this reason, the FDA has restricted the use of the Johnson & Johnson vaccine to adults who otherwise would not receive a COVID vaccination (since the risks of harm from COVID are much, much greater).

On May 5, 2022, the FDA limited the authorized use of the Johnson & Johnson COVID-19 vaccine to:

  • Adults (18 or older) who cannot receive the Pfizer or Moderna vaccines (either because of availability or health reasons)
  • Adults (18 or older) who choose the Johnson & Johnson vaccine or not receiving any vaccine at all.

If you are considering receiving the Johnson & Johnson vaccine, please consult with your doctor to see if it’s a good choice for you.

It’s important to note that the American Society of Hematology, the CDC, and the FDA agree that it’s still important to get vaccinated and boosted because the possible outcomes of COVID-19, which also includes thrombosis, far outweigh the very low risk of TTS following vaccination.

As of January 27, 2022, more than 517 million doses of the Moderna have been given in the US. Of those 517+ million doses, there have been 3 confirmed cases of people developing TTS after receiving the Moderna vaccine. However, it should be noted, it has not been determined if the timing was coincidental or if there was a connection between the Moderna vaccine and the TTS onset. There have been no reports of blood clots with the Pfizer vaccine.

Please note, the number of vaccinations and reports of potential health events changes daily. For more current data, please refer to the CDC’s Adverse Events After COVID-19 Vaccination report linked below.

SOURCES: (CDC) (CDC) (Yale Medicine) (FDA)

Updated 05/06/2022