Randomized, double-blind, multicenter study of the immunogenicity and reactogenicity of 17DD and WHO 17D-213/77 yellow fever vaccines in children: implications for the Brazilian National Immunization Program.
Vaccines against yellow fever currently recommended by the World Health Organization contain either virus sub-strains 17D or 17DD. In adults, the 17DD vaccine demonstrated high seroconversion and similar performance to vaccines manufactured with the WHO 17D-213/77 seed-lot. In another study, 17DD vaccine showed lower seroconversion rates in children younger than 2 years. Data also suggested lower seroconversion with simultaneous application of measles vaccine. This finding in very young children is not consistent with data from studies with 17D vaccines. A multicenter, randomized, double-blind clinical trial was designed (1) to compare the immunogenicity and reactogenicity of two yellow fever vaccines: 17DD (licensed product) and 17D-213/77 (investigational product) in children aged 9-23 months; (2) to assess the effect of simultaneous administration of yellow fever and the measles-mumps-rubella vaccines; and (3) to investigate the interference of maternal antibodies in the response to yellow fever vaccination. The anticipated implications of the results are changes in vaccine sub-strains used in manufacturing YF vaccine used in several countries and changes in the yellow fever vaccination schedule recommendations in national immunization programs.
D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology; D001938:Brazil; D004311:Double-Blind Method; D004340:Drug Contamination; D006801:Humans; D017589:Immunization Programs; D007223:Infant; D009841:Oligonucleotides / Q000032:analysis; D009843:Oligoribonucleotides / Q000032:analysis; D011446:Prospective Studies; D014765:Viral Vaccines / Q000008:administration & dosage / Q000592:standards; D015004:Yellow Fever / Q000276:immunology* / Q000517:prevention & control; D022341:Yellow Fever Vaccine / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D015005:Yellow fever virus / Q000276:immunology*
D000914:Antibodies, Viral; D009841:Oligonucleotides; D009843:Oligoribonucleotides; D014765:Viral Vaccines; D022341:Yellow Fever Vaccine