Spacing of Immunobiologics

Simultaneous Administration

All commonly used vaccines can safely and effectively be given simultaneously (that is, on the same day) without impairing antibody responses or increasing rates of adverse reactions. This knowledge is particularly helpful for international travellers for whom exposure to several infectious diseases might be imminent.

In general, inactivated vaccines may be administered simultaneously at separate sites. However, when vaccines commonly associated with local or systemic reactions are given simultaneously, reactions can be accentuated.

Simultaneous administration of acellular pertussis (DTaP); inactivated poliovirus (IPV); Haemophilus influenzae type b (Hib); measles, mumps, and rubella (MMR); varicella; pneumococcal conjugate; and hepatitis B vaccines is encouraged for persons who are the recommended age to receive these vaccines and for whom no contraindications exist.

Yellow fever vaccine may be administered simultaneously with all other currently available vaccines.

Limited data suggest that the immunogenicity and safety of Japanese encephalitis (JE) vaccine are not compromised by simultaneous administration with DTaP or whole-cell pertussis (DTP) vaccine. No data exist on the effect of concurrent administration of other vaccines, drugs (e.g., chloroquine or mefloquine), or biologicals on the safety and immunogenicity of JE vaccine.

Inactivated vaccines generally do not interfere with the immune response to other inactivated or live-virus vaccines. An inactivated vaccine may be given either simultaneously or at any time before or after a different inactivated vaccine or a live-virus vaccine.

The immune response to an injected live-virus vaccine (e.g., MMR, varicella, or yellow fever) might be impaired if administered within 28 days of another live virus vaccine. Whenever possible, injected live-virus vaccines administered on different days should be given at least 28 days apart. If two injected live-virus vaccines are not administered on the same day but <28 days apart, the second vaccine should be readministered at least 4 weeks later.

Live-virus vaccines can interfere with a person's response to tuberculin testing. Tuberculin testing, if otherwise indicated, can be done either on the day that live-virus vaccines are administered or 4-6 weeks later.