Mutual interference on the immune response to yellow fever vaccine and a combined vaccine against measles, mumps and rubella

► Yellow fever vaccines (YFV) were given either simultaneously or 30 days after a combined measles-mumps-rubella vaccine (MMR) to compare their immunogenicity and reactogenicity in children. ► The immune response to YFV was substantially weaker when given simultaneously to MMR. ► The immune response to the rubella and mumps components of MMR was also weaker with simultaneous administration of YFV. ► Immune response to the measles component was strong regardless of time interval between vaccines.