title: Is early measles vaccination better than later measles vaccination?
abstract: WHO recommends delaying measles vaccination (MV) until maternal antibody has waned. However, early MV may improve child survival by reducing mortality from conditions other than measles infection. We tested whether early MV improves child survival compared with later MV. We found 43 studies comparing measles-vaccinated and measles-unvaccinated children; however, only 16 studies had specific information that MV had been provided at 4-13 months of age, many before 9 months of age. In the 10 best studies (4 randomized trials and 6 observational studies) control children did not receive MV during follow-up. In eight of these studies the vaccine efficacy against death (VED) was 60% or more. In four studies with information on MV provided both before and after 12 months of age, the all-cause mortality reduction was significantly larger for children vaccinated in infancy (VED=74%; 95% CI 51-86%) than for children vaccinated after 12 months of age (VED=29%; CI 8-46%). Prevention of measles explained little of the reduction in mortality. In five studies with information on measles infection, VED was 67% (51-78%) and when measles deaths were excluded, VED was only reduced to 65% (47-77%). One natural experiment compared MV at 4-8 months versus MV at 9-11 months of age and found significantly lower all-cause mortality with early vaccination, the difference being 39% (8-60%). Child mortality may be reduced if MV is given earlier than currently recommended by international organizations.
authors.affiliation: Bandim Health Project, Indepth Network, Apartado 861, Bissau, Guinea-Bissau Research Centre for Vitamins and Vaccines (CVIVA), Bandim Health Project, Statens Serum Institut, Artillerivej 5, 2300 Copenhagen S, Denmark p.aaby@bandim.org.
authors.forename: Peter
authors.initials: P
authors.lastname: Aaby
authors.affiliation: Bandim Health Project, Indepth Network, Apartado 861, Bissau, Guinea-Bissau.
authors.forename: Cesário L
authors.initials: CL
authors.lastname: Martins
authors.affiliation: Research Centre for Vitamins and Vaccines (CVIVA), Bandim Health Project, Statens Serum Institut, Artillerivej 5, 2300 Copenhagen S, Denmark.
authors.forename: Henrik
authors.initials: H
authors.lastname: Ravn
authors.affiliation: Bandim Health Project, Indepth Network, Apartado 861, Bissau, Guinea-Bissau.
authors.forename: Amabelia
authors.initials: A
authors.lastname: Rodrigues
authors.affiliation: The London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
authors.forename: Hilton C
authors.initials: HC
authors.lastname: Whittle
authors.affiliation: Bandim Health Project, Indepth Network, Apartado 861, Bissau, Guinea-Bissau Research Centre for Vitamins and Vaccines (CVIVA), Bandim Health Project, Statens Serum Institut, Artillerivej 5, 2300 Copenhagen S, Denmark.
authors.forename: Christine S
authors.initials: CS
authors.lastname: Benn
mesh_terms: D000914:Antibodies, Viral / Q000276:immunology*; D002675:Child, Preschool; D006801:Humans; D007112:Immunity, Maternally-Acquired / Q000276:immunology*; D007115:Immunization Schedule; D007117:Immunization, Secondary / Q000706:statistics & numerical data*; D007223:Infant; D008457:Measles / Q000401:mortality / Q000517:prevention & control*; D008458:Measles Vaccine / Q000008:administration & dosage* / Q000276:immunology; D016019:Survival Analysis; D014611:Vaccination
chemical_list: D000914:Antibodies, Viral; D008458:Measles Vaccine
keywords: Early vaccination; Measles vaccination; Non-specific effects