https://apnews.com/713648bdba0d622e9cbf5144203ce699

A third dose of Moderna’s COVID-19 vaccine substantially improved protection for organ transplant recipients whose weak immune systems don't always rev up enough with the standard two shots, Canadian researchers reported Wednesday.

The study, published in the New England Journal of Medicine, was small but it’s the most rigorous type of third-dose testing so far for this vulnerable group.