RESUMO
OBJECTIVE: To determine the safety, immunogenicity, and efficacy of revaccination of children with live attenuated influenza vaccine. STUDY DESIGN: A 2-year multicenter, double-blind, placebo-controlled, efficacy field trial of live attenuated, cold-adapted trivalent influenza vaccine administered by nasal spray to children. This report summarizes year 2 results, a year in which the epidemic strain of influenza A/Sydney was not well matched to the vaccine strains. Each year, vaccine strains were antigenically equivalent to the contemporary inactivated influenza vaccine. In year 2, a single intranasal revaccination was administered. Active surveillance for influenza was conducted during the influenza season by means of viral cultures. Influenza cases were defined as illnesses with wild-type influenza virus isolated from respiratory secretions. RESULTS: In year 2, 1358 (85%) children, 26 to 85 months of age, returned for revaccination. The intranasal vaccine was easily accepted, well tolerated, and immunogenic. Revaccination resulted in 82% to 100% of the vaccinated children in a subset studied for immunogenicity being seropositive as compared with 26% to 65% of placebo recipients, depending on the influenza strain tested. No serious adverse events were associated with the vaccine. In addition to the strains in the vaccine, antibody was induced to the variant strain A/Sydney/H3N2. In year 2, influenza A/Sydney/H3N2, a variant not contained in the vaccine, caused 66 of 70 cases of influenza A; nonetheless, intranasal vaccine was 86% efficacious in preventing A/Sydney influenza. Eight cases of lower respiratory tract disease were associated with A/Sydney influenza; all cases were in the placebo group. CONCLUSIONS: This live attenuated, cold-adapted influenza vaccine was safe, immunogenic, and efficacious against influenza A/H3N2 (including a variant, A/Sydney, not contained in the vaccine) and influenza B. The characteristics of this vaccine make it suitable for routine use in children to prevent influenza.
Assuntos
Vírus da Influenza A/imunologia , Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Vacinação , Administração Intranasal , Criança , Pré-Escolar , Temperatura Baixa , Método Duplo-Cego , Feminino , Humanos , Vírus da Influenza B/imunologia , Masculino , Estudos Prospectivos , Vacinas AtenuadasRESUMO
Respiratory syncytial virus causes worldwide epidemics of respiratory disease. Of 23 children infected with respiratory syncytial virus, 65% had low serum concentrations of vitamin A during acute illness; these low values were associated with more severe illness. Vitamin A supplementation may have a role in the management of infection with respiratory syncytial virus.
Assuntos
Infecções por Vírus Respiratório Sincicial/sangue , Vitamina A/sangue , Estudos de Casos e Controles , Humanos , Lactente , Recém-NascidoRESUMO
We performed serial serologic tests for cytomegalovirus (CMV) antibody in 177 children born to low- and middle-income families in Houston from 1975 to 1983. Mean duration of participation in the study was 4.8 years (range 1 to 9.6 years). Most rapid acquisition of antibody occurred during the first and second years of life, 13.6% and 12%, respectively; thereafter, annual acquisition varied from 1.5% to 4.6%, up to 10 years. Overall, 59 (33%) of the group were known to seroconvert by age 10 years. This was a minimal figure because of loss to follow-up. Analysis by the Kaplan-Meier method indicated that the probability of remaining seronegative was 65% at age 6 years, and 58% at age 8 years. Variables positively related to seroconversion by multivariate analysis were order of birth, seroconversion in a family member, and breast-feeding. During the first year of life, acquisition of CMV antibody was related to the seroimmune status of the mother. The variables of socioeconomic status, race, age of the mother, and attendance in a day care center did not appear to be related to seroconversion in these children.