The FDA followed suit with the CDC to recommend the mRNA vaccines over the J&J vaccine due to the risk of TTS.
People who are contraindicated for other vaccines or who would otherwise not get vaccinated can still choose J&J. But everyone else should get a different type of vaccine.
This follows a review of the latest data on the risk of TTS. And namely that at present we don't know the individual risk factors that lead some people to experience TTS.
The benefit of vaccination with J&J still outweighs the risk of coronavirus infection, so the FDA recommends people get the J&J vaccine over going unvaccinated.
According to US data through March 18, 2022, 60 people have suffered TTS and 9 people have died from it. The risk of TTS is 3.23 per million doses of J&J. And the risk of TTS death is 0.48 per million doses.
If you recall TTS is a rare clotting adverse event after vaccination. It occurs in the first week or two after vaccination with the adenovirus vector coronavirus vaccines from J&J and AstraZeneca. Proper identification is critical as standard treatment for the typical non-vaccine condition is harmful. Even with proper treatment the risk of death is high, and patients can suffer severe long-term complications.