Theoretically, it is preferable to separate the administration of different live virus vaccines by at least one month. However, extensive experience has demonstrated that measles, mumps, and rubella vaccines can be combined and that OPV can be administered simultaneously with MMR vaccine without diminished efficacy or increased toxicity. Live vaccine and inactivated vaccine can be administered simultaneously at separate injection sites, except for cholera and yellow fever vaccines, which should be administered at least three weeks apart to ensure an optimal antibody response. Two or more inactivated vaccines can also be administered simultaneously. However, if significant local or systemic reactions are anticipated, as is often the case with cholera or typhoid vaccine, for example, it is best to administer the vaccines on separate days.
Passive immunization can interfere with active immunization.
This interference is minor with inactivated vaccines, which therefore may be administered anytime before or after use of immune globulin. However, the administration of a live vaccine should be delayed for at least six weeks, preferably for three months, after treatment with immune globulin, blood, or plasma. If such a delay is not possible because of imminent danger of infection, the vaccine should be administered at a site remote from the immune globulin injection site, and vaccination should be repeated in three months unless serologic test results demonstrate adequate levels of antibody production. Travelers and other persons who require both vaccine and immune globulin should be given the vaccine at least 14 days before receiving the immune globulin. However, immune globulin does not interfere with the efficacy of OPV, yellow fever, or oral typhoid vaccinations, which may therefore be administered before, with, or after immune globulin administration.