Appropriate medical treatment must be immediately available in the event an anaphylactic reaction occurs following administration. Increased risk of Guillain-Barré syndrome during 42 days following vaccination. Syncope may occur; put procedures in place 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. Potential risk of preterm birth. Pregnant individuals <24 wk gestational age & those at increased risk of preterm birth. Lactation. Non-pregnant individuals <18 yr. Childn <10 yr.