Safety of Administering MR and DPT Vaccines 19 Days Apart
General Principles for Vaccine Administration Timing
- The Advisory Committee on Immunization Practices (ACIP) guidelines indicate that inactivated vaccines, like DPT, may be administered at any time before or after a different inactivated or live vaccine, like MR, unless a specific contraindication exists 1
- Longer-than-recommended intervals between doses do not reduce final antibody concentrations, so an interruption in the immunization schedule does not require reinstitution of the entire series 2
Specific Considerations for MR and DPT Vaccines
- DPT is an inactivated vaccine while MR contains live attenuated viruses 4, 5
- Since DPT is not a live virus vaccine, there is no immunological concern about administering it 19 days after or before MR vaccine 6, 1
Evidence Supporting Safety of This Schedule
- Simultaneous administration of DTP, MMR, and other vaccines has resulted in seroconversion rates and rates of adverse reactions similar to those observed when the vaccines are administered separately 4
- Clinical experience has strengthened the scientific basis for administering vaccines at different intervals without compromising effectiveness or safety 7
Potential Concerns and How to Address Them
- Certain vaccines, including tetanus toxoid-containing vaccines like DPT, can produce increased rates of local or systemic reactions in certain recipients when administered too frequently due to antigen-antibody complex formation 7
- Optimal record keeping, maintaining patient histories, and adhering to recommended schedules can decrease the incidence of such reactions without adversely affecting immunity 6
Best Practices for Administration
- Ensure that the full recommended dose of each vaccine is administered (do not use reduced volumes) 4