As federal officials consider COVID booster shots for all Americans, certain immunocompromised individuals began receiving a third dose of the mRNA vaccines this week following approvals from the FDA and CDC late last week. Onisis Stefas, PharmD, chief pharmacy officer for Northwell Health, explains the need for booster shots, who is eligible now and what else immunocompromised individuals can do to protect themselves against COVID-19, especially the delta variant.