Same exact issue as with the AstraZeneca vaccine. Both are vector based adno virus delivery mechanisms. I’d say the J&J shot is probably done in the US minus some unforeseen problems with the other vaccines.
Moral of the story is to diversify and have options.
Some scientists noted that the formulation of Johnson & Johnson and AstraZeneca are very similar. If one vaccine had problems with blood clots then it was likely the other vaccine would have the same issues.
My one question is --- Does this problem cause problems with the U.S. vaccination timeline and effort. We were already getting close to the point where would be more vaccine doses available than people wanting them (projected at the end of April). Does this stop of J&J change any of this -- or will available doses of the two other vaccines cover the elimination of of J&J.