PCV20 Demonstrates Immunogenicity and Safety Comparable With PCV13 in Infants

A phase 3 study evaluating the safety and immunogenicity of the 20-valent pneumococcal conjugate vaccine (PCV20) in infants found that PCV20 met noninferiority (NI) criteria for all 20 serotypes in immunoglobulin G (IgG) geometric mean concentrations after both the third and fourth doses. The vaccine elicited robust immune responses across serotypes and had a safety profile similar to the 13-valent pneumococcal conjugate vaccine (PCV13), supporting its potential to broaden protection against pneumococcal disease in infants and young children.

PCV20 was developed to provide expanded coverage against pneumococcal disease compared with PCV13. While PCV13 has been widely used in infant vaccination programs, additional serotypes remain associated with pneumococcal disease burden. This study was conducted to evaluate whether PCV20 elicits comparable immune responses to PCV13 while providing coverage against seven additional pneumococcal serotypes.

In this phase 3, double-blind study conducted in the United States and Puerto Rico, healthy infants were randomized to receive either PCV20 or PCV13 in a four-dose series at 2, 4, 6, and 12–15 months of age. Immunogenicity was assessed by measuring IgG geometric mean concentrations one month after doses three and four and evaluating the percentage of participants who achieved predefined IgG concentration thresholds after dose three. Noninferiority criteria were based on predefined confidence interval thresholds. Safety assessments included local and systemic reactions, adverse events, serious adverse events, and newly diagnosed chronic medical conditions.

A total of 1991 infants were vaccinated (PCV20, n = 1001; PCV13, n = 990). PCV20 met NI criteria for all 20 serotypes in IgG geometric mean concentrations 1 month after both doses three and four. Additionally, for the percentage of participants achieving predefined IgG concentrations after dose three, PCV20 met NI criteria for eight of 13 matched serotypes and six of seven additional serotypes. Four serotypes narrowly missed statistical NI thresholds. The vaccine elicited functional and boosting responses for all 20 serotypes. The safety profile of PCV20 was comparable with PCV13, with no unexpected adverse events reported.

“A four-dose series of PCV20 was well tolerated and elicited robust serotype-specific immune responses expected to help protect infants and young children against pneumococcal disease due to the 20 vaccine serotypes,” the study authors concluded.

Reference

Senders S, Klein NP, Tamimi N, et al. A phase three study of the safety and immunogenicity of a four-dose series of 20-valent pneumococcal conjugate vaccine in healthy infants. Pediatr Infect Dis J. 2024;43(6):596-603 doi:10.1097/INF.0000000000004334Top of Form