Procedures
VIROSIS, DISEASES, VIRUS, MEASLES, MEASLES, ADVERSE EVENT, MUMPS, RUBELLA, PLAQUE, BLOOD
At the baseline visit, study physicians performed a brief clinical history and exam. A 5 ml venous blood sample was collected, and children were vaccinated with MMR, YF vaccine, or both depending on their randomization group. Vaccination procedures followed the 2012 edition of the Argentinian National Immunization Guidelines [At 28–35 days (Visit 2), all children returned for a follow-up venous blood draw of up to 5 ml. Children in the MMRSamples were refrigerated at the study sites and transported within 24 h to the Central Blood Bank of Misiones Province. Samples were centrifuged at either the study site or the Blood Bank, and serum was separated and stored at 2–8 °C at the Blood Bank. Serum was flown to the Instituto Nacional de Enfermedades Infecciosas, Administración Nacional de Laboratorios e Institutos de Salud “Dr. Carlos Malbrán” (ANLIS) in Buenos Aires twice a week, where serum was aliquoted into separate cryovials for MMR and YF testing and then stored at -70 °C until testing was performed.Parents were informed about potential local and systemic reactions to vaccination and asked to notify the study staff of any serious adverse event, as defined by national authorities [Measles and rubella testing was performed at the Servicio de Virosis Respiratorias and mumps testing was performed at the Servicio de Neurovirosis, both within the Instituto Nacional de Enfermedades Infecciosas, ANLIS. Quantitative enzyme immunoassay (ELISA) IgG kits manufactured by Siemens (Marburg, Germany) were used to measure IgG antibody concentrations against measles, mumps, and rubella.YF testing was performed at the CDC Arbovirus Diseases Laboratory, Fort Collins, Colorado, USA. Paired baseline and follow-up samples were tested for the presence of neutralizing antibodies against YF 17-D 204 virus, using the plaque reduction neutralization test with cut-offs of 50% (PRNT