New Choices in Pneumococcal Vaccines: A 4-question Quiz

The Advisory Committee on Immunization Practices (ACIP) issued its new pneumococcal vaccine recommendations, made necessary by the FDA approval in 2021 of 2 new conjugate pneumoccal vaccines: Prevnar 20 (PCV20) and Vaxneuvance (PCV15). The first protects against 20 pneumoccal strains, the second against 15.

The approval was based on studies that compared antibody responses to PCV20 and PCV15 with those to Prevnar 13® (PCV13), which is still used in persons aged ≤18 years but no longer recommended for adults. The approvals offered an opportunity to review ACIP’s existing recommendations and available data on the current pneumococcal vaccines. Pneumovax® (PPSV23) protects against 23 strains, but is a polysaccharide vaccine and does not stimulate memory B cells like the conjugate vaccines. Antibody studies done in older adults with PPSV23 show a decline in levels to pre-vaccine levels in 4 to 7 years. Observational studies of clinical effectiveness generally suggest a decline of effectiveness with time since administration, which is what would be expected with a polysaccharide vaccine. Prevnar 20 is currently in phase 3 trials for use in children.

Let's see what you know about the new vaccines and ACIP recommendations with the 4-question quiz below.

1. Which of the following is true?