title: Immunization of high-risk infants younger than 18 months of age with split-product influenza vaccine.
abstract: Influenza is an important cause of serious illness in very young children with cardiopulmonary disease. A 4-year study was conducted at two centers to assess immunogenicity and safety of influenza split-product vaccine in children aged 3 to 18 months with bronchopulmonary dysplasia and congenital heart disease. A total of 113 children were studied: 62 children 3 to 5 months of age and 51 children 6 to 18 months of age. Sera were drawn prior to first and second immunization and 3 weeks after second immunization and were tested by hemagglutination inhibition; protection was defined as greater than 1:32. Ninety-five children were surveyed for adverse reactions. Seroresponses were age and antigen specific. Best responses for all ages were to A/Mississippi (H3N2) (97%). Children older than 6 months of age had better seroresponses to A/Leningrad (H3N2) (73%, P less than .03) and B/Victoria (62%, P less than .02) than did children younger than 6 months of age. Seroconversion rates to the remaining antigens were low. Only 9% of children experienced adverse reactions; all but one were mild. The immunologic mechanisms responsible for preventing serious influenzal disease and more effective immunization strategies need to be defined for very young high-risk children.
authors.affiliation: Department of Pediatrics, University of Colorado School of Medicine, Denver.
authors.forename: J R
authors.initials: JR
authors.lastname: Groothuis
authors.forename: M J
authors.initials: MJ
authors.lastname: Levin
authors.forename: G P
authors.initials: GP
authors.lastname: Rabalais
authors.forename: G
authors.initials: G
authors.lastname: Meiklejohn
authors.forename: B A
authors.initials: BA
authors.lastname: Lauer
mesh_terms: D000375:Aging / Q000276:immunology; D001997:Bronchopulmonary Dysplasia / Q000276:immunology; D005260:Female; D006330:Heart Defects, Congenital / Q000276:immunology; D006386:Hemagglutination Tests; D006801:Humans; D007114:Immunization; D007223:Infant; D007231:Infant, Newborn; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology; D007251:Influenza, Human / Q000517:prevention & control*; D008297:Male; D011446:Prospective Studies
chemical_list: D007252:Influenza Vaccines