Because she has functional asplenia, she is due for the second dose of the primary series (assuming 8 weeks have passed since the first primary series dose). Because she has a high-risk medical condition she will need periodic booster doses. If she is younger than age 7 years when she receives the second dose of her primary series, she should receive her first booster dose 3 years after completing the primary series. She should then receive a booster dose every five years thereafter. If she is age 7 years or older when she receives the second primary dose she should receive her first booster dose 5 years after the completing the primary series and every five years thereafter.