The continued emergence of non-vaccine types pneumococcal strains prompted the development of new pneumococcal vaccines. Merck received FDA approval in July 2021 for a 15-valent pneumococcal vaccine, PCV15, for use in adults 18 years and older This vaccine adds strain 22F and 33F to the 13 strains currently found in PCV13. In June 2022, the FDA approved use of PCV15 for individuals six weeks of age and older.
Pfizer (Wyeth) was awarded Breakthrough Therapy Designation by the FDA for a new 20-valent pneumococcal vaccine in September 2018. Breakthrough Therapy Designation allows drug companies the opportunity to expedite the development and review of drugs that are intended to treat a serious condition and preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over available therapy on a clinically significant endpoint(s).
On June 10, 2021, the FDA approved Prevnar 20 (PCV20) for use in adults 18 and older. PCV20 adds strains 8, 10A, 11A, 12F, 15B, 22F, 33F to the 13 strains found in PCV13.
On October 20, 2021, ACIP voted to recommend that all adults 65 years of age and older who have not previously received a dose of pneumococcal conjugate vaccine be given a dose of PCV15 or PCV20. If PCV15 is administered, the CDC recommended that a dose of PPSV23 be given, at least one year after PCV15. The interval, however, could be shortened to eight weeks in persons who are immunocompromised. Persons 19 through 64 years with pre-existing health conditions that put them at an increased risk of invasive pneumococcal disease and who had not previously received a dose of pneumococcal conjugate vaccine were also recommended vaccination with PCV15 or PCV20. For individuals who received a dose of PCV15, a dose of PPSV23 was also recommended, to be given at least one year apart.
In all clinical trials, the immune responses to PCV15 and PCV20 were reported to be non-inferior to PCV13. There are, however, no established corelates of protection that ensure an individual is protected from invasive pneumococcal disease.
PCV15 and PCV20 were developed to target additional pneumococcal strains not covered by PCV13 but there is a lack of clinical data to determine whether PCV15 and PCV20 will prevent invasive pneumococcal disease caused by the strains targeted by these vaccines. Additionally, while the CDC is recommending use of PCV20 vaccine for children with risk factors for pneumococcal disease, there is a lack of clinical data to support this recommendation since clinical trials did not involve high-risk children.
