When PCV15 is given to an adult 65 years or older, PCV15 should be given first followed by PPSV23 one year later (an 8-week minimum interval may be considered for immunocompromised recipients).
What to do when doses of PPSV23 and PCV15 are given without the recommended minimum interval is not addressed in the ACIP recommendations. The CDC subject matter experts have advised that in such a case, the dose given second does not need to be repeated. This is an exception to the usual procedure for a minimum interval violation as described in ACIP’s “General Best Practices Guidelines for Immunization” (see www.cdc.gov/vaccines/hcp/acip-recs/general-recs/timing.html). There is no evidence to support that there are benefits to repeating the dose of PCV15.