The 20-valent pneumococcal conjugate vaccine (PCV20, or Prevnar 20) produced a non-inferior immune response in adults to the 13-valent vaccine (PCV13, or Prevnar 13), with an adequate safety profile, a phase III trial found.
One dose of PCV20 produced immune responses comparable to the 13 matched serotypes in PCV13 a month later among adults ages 60 and older, as well as immune responses to six of seven additional serotypes, reported Charu Sabharwal, MD, of Pfizer in Pearl River, New York, and colleagues.
Moreover, adults ages 18-59 who received PCV20 produced immune responses comparable to all 20 serotypes as adults ages 60-64 a month later, the authors wrote in
PCV20 also had a comparable safety profile to PCV13 among adults, with fewer than 2% of patients across groups reporting vaccine-related adverse events (AEs), the team noted.
FDA in June 2021, and in October 2021, CDC's Advisory Committee on Immunization Practices (ACIP) streamlined pneumococcal vaccine recommendations to include PCV20. ACIP said that all adults ages 65 and up and certain adults ages 19-64 with medical conditions or PCV15 (Vaxneuvance). If PCV15 is used, it should be followed by polysaccharide vaccine (Pneumovax 23, or PPSV23), the committee said.
Sabharwal's group noted that their phase III trial was among the evidence presented to the agency to support the approval of PCV20 for use in adults.
The was conducted in the U.S. and Sweden. From December 2018 to December 2019, healthy adults ages 18 and older were randomized into three age-based cohorts: 18-49, 50-59, and 60 and up.
Those ages 60 and older were randomized 1:1 to receive one dose of either PCV20 or PCV13 and one dose of either PPSV23 or placebo a month later, while those ages 18-59 were randomized 3:1 to receive either one dose of PCV20 or PCV13.
The primary immunogenicity objective was non-inferior immune responses elicited by PCV20 to the 13 corresponding serotypes after PCV13, and the seven additional serotypes prior to vaccination with PPSV23.
Safety objectives examined the percentages of participants with solicited local and systemic reactions 7-10 days later, AEs within a month, and severe AEs and newly diagnosed chronic medical conditions within 6 months.
Overall, 2,835 older adults completed the study. About two-thirds of this population were ages 60-64, and about 31% were ages 65-79. U.S. participants comprised about 83% of the study population. There were 432 adults ages 50-59 and 423 adults ages 18-49 who completed the study, the authors noted.
Non-inferiority criteria were met for 13 matched serotypes among older adults, though Sabharwal's group noted that while both PCV20 and PCV13 groups had similar percentages of a more than four-fold rise in serotype-specific geometric mean titers, they were "slightly lower" among the PCV20 group.
Likewise, non-inferiority criteria were met for six of seven additional serotypes, though not serotype 8, with "robust increases" in geometric mean titers against all seven serotypes a month after vaccination versus baseline, the authors said.
Examining safety, most local and systemic events were mild to moderate. Muscle pain was the most common systemic AE, and about 1%-2% of adults in the PCV13 and PCV20 groups experienced fever. No severe AEs or new chronic medical conditions were judged to be vaccine-related, the authors added.
Eleven participants receiving PCV20/saline discontinued due to AEs, five of which were judged to be vaccine-related. Three of those were redness or swelling with or without pruritus at the injection site. Of the eight AEs in the PCV13/PPSV23 group, four were judged to be vaccine-related: injection site pain, muscle pain, reactivity, and bronchial hypersensitivity.
Disclosures
The study was supported by Pfizer, Inc.
Sabharwal and several co-authors are employees of Pfizer; one co-author disclosed PATH grant support for Nipah vaccine, Meissa grant support for RSV vaccine, Emergent grant support for Chikungunya vaccine, as well as support from Sanofi, Johnson & Johnson, Merck, and Seqirus.
Primary Source
Clinical Infectious Diseases
Essink B, et al "Pivotal phase 3 randomized clinical trial of the safety, tolerability, and immunogenicity of 20-valent pneumococcal conjugate vaccine in adults 18 years and older" Clin Infect Dis 2021; DOI: 10.1093/cid/ciab990.