Vaccine. 2025 Feb 15:126815. doi: 10.1016/j.vaccine.2025.126815. Online ahead of print.
ABSTRACT
BACKGROUND: A novel 13-valent pneumococcal conjugate vaccine (PCV13-TT) has been widely used in China since its licensure in 2019. The prelicensure pivotal clinical study (PCV13-002) showed strong immune responses against 13 serotypes with PCV13-TT using two different 3P + 1 schedules starting at either 2 (PCV13-2M) or 3 months (PCV13-3M) of age.
METHODS: To assess antibody persistence, healthy Chinese toddlers from PCV13-002 were recalled for blood collection at 1 and 2 years post booster dose. Antibody persistence was evaluated using ELISA and OPA assay methods to measure serotype-specific antibodies.
RESULTS: Similar immune responses were noted for both PCV13-3M and PCV13-2M groups. IgG GMCs remained high (ranging from 0.39 to 4.68 μg/mL) through 2 years post 4 doses of PCV13-TT, with IgG positive rates against most serotypes maintained at ≥90%. Both OPA GMTs and OPA positive rates remained high compared to levels observed at 1 month post booster.
CONCLUSION: After complete dosing schedule of PCV13-TT starting from either 2 months or 3 months, the antibody level declined through 1 year and 2 years post booster dose, while still remained at relatively high levels at the two timepoints as compared to those observed at 1 month post booster dose for the majority of serotypes.
CLINICAL TRIAL REGISTRATION: CTR20182353.
PMID:39956719 | DOI:10.1016/j.vaccine.2025.126815
