Catch-up Vaccination Planner
Guidelines for missed or delayed doses
Golden Rule of Catch-up Vaccination
Do not restart a vaccine series regardless of the time that has elapsed between doses (with very few exceptions, like oral typhoid). Simply continue the series from where the patient left off, adhering to the minimum recommended intervals between doses.
Minimum Intervals
When accelerating a schedule for a patient behind on vaccines, you must respect absolute minimum intervals. Giving a dose before the minimum interval can result in a suboptimal immune response, requiring the dose to be repeated.
- Live Vaccines: If two live injected/intranasal vaccines are not given on the same day, they must be separated by at least 28 days (4 weeks).
- Hep B: Minimum 4 weeks between dose 1 and 2; 8 weeks between dose 2 and 3; and 16 weeks between dose 1 and 3.
Common Scenarios
Missed childhood MMR
Adults born after 1957 without evidence of immunity should get at least 1 dose of MMR. Healthcare workers need 2 doses.
Unknown vaccination history
Generally, patients with completely unknown histories should be considered susceptible and started on an age-appropriate catch-up schedule. Serologic testing can sometimes be used (e.g., Varicella, MMR, HepB) to prove immunity.