Appropriate medical treatment must be immediately available in the event an anaphylactic reaction occurs following administration. Potential risk of preterm birth. Syncope may occur; place procedures to avoid injury from fainting. Immunocompromised individuals including those receiving immunosuppressive therapy may have diminished immune response to Abrysvo. May not protect all vaccine recipients. Pregnant individuals <24 wk gestational age & those at increased risk of preterm birth. Lactation. Non-pregnant individuals <18 yr. Childn <10 yr.