Our adult patient has been accepted to a physician assistant program that requires polio vaccine for all students. She has 2 documented doses of oral polio vaccine (OPV) as a child, then recently had a dose of inactivated polio vaccine (IPV). How many more doses of IPV does she need to complete the series and on what schedule?

People who receive a mixed series of OPV and IPV should receive a total of either 3 or 4 doses depending on the age at the time of the last dose. In this case the recent dose of IPV can be counted as the third and final dose in the series. The minimum interval between the next-to-last and last doses in the polio vaccination series is 6 months and the last dose should be at age 4 years or older.