How well do Covid vaccines protect after organ transplant?

A new study raised questions about how well Covid-19 vaccines protect organ transplant recipients — and what precautions people with suppressed immune systems should take after the shots.

Vaccines rev up the immune system to recognize the virus, something that's harder to do if someone’s immune cells aren’t in good working order. Transplant recipients take powerful immune-suppressing drugs to prevent organ rejection, which also increases their risk from the coronavirus — but excluded them from vaccine studies.