The problem with Johnson & Johnson Covid vaccine
Recently, the U.S. Bishops issued a joint statement regarding the complicated moral problem of taking some Covid vaccines.
The summary version is that all three of the Covid vaccines currently being offered have at least indirect moral problems, but that the Johnson & Johnson vaccine is the one with the most serious moral problems. They are encouraging Catholics NOT to take the Johnson & Johnson vaccine if there is alternative available (such as the Pfizer and Moderna vaccines).
The reason is that Johnson & Johnson is the one that most directly uses cells from aborted children in the research, development and production processes.
As you can see from the statement, their analysis is that taking the vaccines is morally acceptable (not morally obligatory), but that we should do what we reasonably can to prevent them from using immoral means to produce vaccines in the future.