Simultaneous Administration of Live Virus Vaccines

Abstract

A double-blind controlled study was conducted to evaluate the clinical and serologic responses to the simultaneous administration of four live virus vaccines: further attenuated measles, mumps, oral trivalent poliomyelitis, and smallpox. The percent of children with temperatures ≥103 F (39.4 C), 15%, was significantly greater among recipients of simultaneous vaccines than among those receiving placebos, 4%. However, there was no significant difference in the percent of temperatures ≥103 F between simultaneous vaccine recipients and children receiving a single vaccine. The serologic response to measles and smallpox vaccines given singly or simultaneously was in excess of 93%, while seroconversion rates for mumps vaccine given alone and simultaneously were 93% and 86%, respectively. The frequency distributions of antibody titers to each antigen, whether administered simultaneously or singly, were similar. No evidence of viral interference or increased severity of adverse reactions was noted when the four vaccines were given simultaneously.