The Food and Drug Administration's decision to take the Johnson and Johnson vaccine out of the American market briefly to look into blood clotting is verification that vaccination system is working well, according to Sociology Professor Jennifer Reich. The pause gave the FDA an opportunity to make sure "vaccines remain exquisitely safe." Even with a highly powered clinical trial, she said, you can only learn so much with 30,000 participants. 

Why the Johnson & Johnson news feels so bad

USA Today (EU), April 16