Participants
allergic, allergy, anaphylactic reaction
IMMUNODEFICIENCY DISORDER, ALLERGY, RECRUITMENT, ANAPHYLACTIC REACTION
Infants with no clinically significant maternal or perinatal history born at 36 weeks' gestation or more were recruited by community health staff in districts 4, 7, and 8 of Ho Chi Minh City at 2 months of age and followed up to 24 months. Exclusion criteria included known allergy to any vaccine component, allergic or anaphylactic reaction to any previous vaccine, known immunodeficiency disorder, mother with a known HIV-positive status, and previous receipt of any routine 2-month vaccines. A parent or guardian provided written informed consent for each participant. Full details of the participant eligibility criteria, recruitment, and consent processes have been described previously.