The Advisory Committee on Immunization Practices has updated its vaccination recommendations for immunocompetent adults aged 65 years or older to extend the interval between receipt of the Prevnar 13 and Pneumovax 23 vaccines to at least 1 year.
The recommendation was changed to mirror the recommended interval for Prevnar 13 (13-valent pneumococcal conjugate vaccine, Pfizer; PCV13) and Pneumovax 23 (23-valent pneumococcal polysaccharide vaccine, Merck; PPSV23) sequence in the same age group, and reflects data that suggest improved immune responses with longer vaccination intervals, the researchers wrote.
“The difference in the recommended interval depending on the order in which the two vaccines were given added significant complexity to the recommendation … for this age group,” the researchers wrote. “To simplify the recommendations, ACIP assessed whether available evidence would support changing the recommended interval for the PCV13–PPSV23 sequence for immunocompetent adults aged [65 years or older].”
If immunocompetent, the previous recommendation for this age group was a dose of PCV13 followed by a dose of PPSV23 at 6 to 12 months later. This recommendation clashed with the yearlong interval recommended to patients who had received PPSV23 before PCV13, the researchers wrote, leading ACIP to update its PCV13–PPSV23 sequence recommendation to a 1 year or greater interval.
No clinical studies evaluating efficacy of the two vaccines given in series were available, resulting in the ACIP referencing immunogenicity studies. Data from 16 of these studies suggested that shorter intervals could be associated with greater local reactogenicity; longer intervals could lead to a superior immune response than a single dose of either vaccine, the researchers wrote.
Other considerations included an increased risk window for infection, timing and reducing visits to vaccination providers and revised CMS regulations that cover two pneumococcal vaccines given in series and administered 1 year apart.
Recommended intervals between PCV13 and PPSV23 delivery remain unchanged for persons aged 2 years or older with medical indications, and PPSV23 is to be given 8 weeks or more after PCV13 for those aged 19 years or older with certain underlying medical conditions.