Study of the Safety and Immunogenicity of Catch-up Vaccination With a 21-valent Pneumococcal Conjugate Vaccine (PCV21) in Healthy Infants, Toddlers, Children, and Adolescents

Study type

Interventional

Primary purpose

Prevention

Allocation

Randomized

Intervention model

Parallel

Masking

Single

Arms

3

Interventions

• PCV21 Biological
• 20vPCV Biological

• Pneumococcal Infections

Primary outcome

Number of participants reporting immediate adverse events (AEs) (Within 30 minutes post-vaccination); Number of participants reporting solicited injection site and solicited systemic reactions (Up to Day 7 post-vaccination); Number of participants reporting unsolicited (spontaneously reported) injection site reactions and unsolicited systemic AEs after each and any injection of a pneumococcal vaccine (Within 30 days after vaccination); Number of participants reporting serious adverse events (SAEs) and adverse events of special interest (AESIs) (From day 0 to day 517); Number of Infants (7-11 months of age [MoA]) and toddlers (12-23 MoA): with serotype-specific IgG concentrations for all serotypes included in PCV21 (On day 30 after last vaccination); Number of Children (2-5 years of age [YoA]):with serotype specific OPA titers for all serotypes included in PCV21 (On day 30); Number of Children (2-5 years of age [YoA]):with serotype specific IgG concentrations for all serotypes included in PCV21 (On day 30); Number of Children/adolescents (6-17 YoA):with serotype specific OPA titers for all serotypes included in PCV21 (On day 30)

• PCV21

• NCT06838000 on ClinicalTrials.gov (opens in a new tab) Licence: public-domain. Read 25 Oct 2026

Source: ClinicalTrials.gov, U.S. National Library of Medicine. Listing a study does not mean NLM has evaluated it.