This patient who will be undergoing splenectomy should receive the pneumococcal conjugate vaccine (PCV13) now, followed by the pneumococcal polysaccharide vaccine (PPSV23) in 8 weeks. Persons with functional or anatomic asplenia are at risk for infection with encapsulated organisms and therefore should be vaccinated against pneumococcus. There are two pneumococcal vaccines: a polysaccharide vaccine composed of capsular material from 23 pneumococcal subtypes (PPSV23) and a conjugate vaccine containing capsular material from 13 pneumococcal subtypes conjugated to a nontoxic protein (PCV13), which increases its immunogenicity. Both pneumococcal vaccines are recommended in these patients; however, when PCV13 is indicated, it should be given before PPSV23. Therefore, administration of PCV13 would be appropriate now, followed by a single dose of PPSV23 8 weeks later. Administration of a second dose of PPSV23 is recommended 5 years after administration of the first PPSV23 dose for patients aged 19 to 64 years who have functional or anatomic asplenia. Furthermore, individuals who receive PPSV23 before age 65 years should receive an additional dose of PPSV23 at age 65 years provided that at least 5 years have passed since the most recent PPSV23 administration. Therefore, this patient should receive a second dose of PPSV23 at age 40 years and a third dose of PPSV23 once he is 65 years of age, provided that he remains on schedule. No additional doses of PCV13 are required.
According to the Advisory Committee on Immunization Practices, PCV13 and PPSV23 should not be administered together. The minimum acceptable interval between administration of PCV13 and PPSV23 is 8 weeks.
PPSV23 should not be the only pneumococcal vaccine administered in patients with asplenia, as it is significantly less immunogenic than PCV13. PPSV23 is only 60% to 70% effective in preventing invasive pneumococcal disease; however, PCV13 is more than 90% effective.
Several large randomized, multicenter trials have shown a decreased serologic response in patients who received PCV13 after PPSV23 compared with those who received PCV13 first; therefore, administration of PPSV23 now and PCV13 in 8 weeks is not recommended.