Single priming and a booster dose of 10-valent and 13-valent pneumococcal conjugate vaccine (PCV) maintains suppression of vaccine serotype colonization in South African children at 3, 4, and 5 years of age: a single-center, open-labeled, randomized trial
Creators: name: Olwagen, Courtney P.
name: Izu, Alane
name: Van der Merwe, Lara
name: Jose, Lisa
name: Koen, Anthonet
name: Madhi, Shabir A.
Publisher: name: Taylor & Francis
Year: 2024
Subjects: subject: Medicine
subject: Microbiology
subject: FOS: Biological sciences
subject: Pharmacology
subject: Biotechnology
subject: Immunology
subject: FOS: Clinical medicine
subject: Cancer
subject: Infectious Diseases
subject: FOS: Health sciences
subject: Virology

description: Surveillance on nasopharyngeal Streptococcus pneumoniae carriage in older children would be informative in determining whether a single priming and booster dose of pneumococcal conjugate vaccine (PCV) provides durable protection against pneumococcal disease compared with traditional dosing schedules. We report on the secondary study objective to evaluate overall, vaccine-serotype (VT) and non-vaccine serotype (NVT) S. pneumoniae colonization at 3, 4, and 5 years of age in children who were randomized to receive 10-valent or 13-valent PCV formulations at 6 (6w + 1) or 14 (14w + 1) weeks compared with a two-dose primary series (2 + 1), with all children receiving a booster dose at 9 months of age, using a multiplex nanofluidic qPCR assay. The prevalence of overall, VT, or NVT at 5 years of age between the 2 + 1 compared with the 6w + 1 or 14w + 1 groups for both PCV10 and PCV13 did not differ. Although inconclusive, our findings suggest that a reduced 1 + 1 PCV dosing schedule is unlikely to increase breakthrough cases of VT pneumococcal disease in older children, which can inform decision-making on transitioning to a 1 + 1 schedule in South Africa. Clinical trial registration: The trial is registered at www.clinicaltrials.gov ;(identifier is NCT04275284). Transition to a 1 + 1 dosing schedule in South Africa could offer significant cost savings while maintaining adequate protection, allowing resources to be allocated for other vaccines in the public immunization program.The lower risk of acquiring PCV13 serotype colonization and disease in South Africa has provided the opportunity to consider transitioning to a reduced 1 + 1 dosing schedule.Initial findings from an open-label, randomized trial indicate that a single priming and booster dose of PCV10 or PCV13 (1 + 1 schedule) is immunologically non-inferior to the 2 + 1 schedule (two priming doses, followed by a booster) one month post-booster. Additionally, there were no significant differences in the acquisition of new vaccine serotype colonization between the study groups for either vaccine formulation up to 18 months of age.In this study, we report that a single priming dose of PCV10 or PCV13 (1 + 1 schedule) results in pneumococcal colonization prevalence similar to that of the 2 + 1 schedule through to five years of age.There was no evidence in this study to indicate that a reduced 1 + 1 dosing schedule will increase vaccine serotype colonization in children up to five years of age. These results, when considered alongside existing immunological data, support the UK’s modeling, suggesting that transitioning from a 2 + 1 to 1 + 1 PCV immunization schedule is unlikely to increase breakthrough cases of VT pneumococcal disease in older children, even in settings with residual PCV13 serotype carriage. Transition to a 1 + 1 dosing schedule in South Africa could offer significant cost savings while maintaining adequate protection, allowing resources to be allocated for other vaccines in the public immunization program. The lower risk of acquiring PCV13 serotype colonization and disease in South Africa has provided the opportunity to consider transitioning to a reduced 1 + 1 dosing schedule. Initial findings from an open-label, randomized trial indicate that a single priming and booster dose of PCV10 or PCV13 (1 + 1 schedule) is immunologically non-inferior to the 2 + 1 schedule (two priming doses, followed by a booster) one month post-booster. Additionally, there were no significant differences in the acquisition of new vaccine serotype colonization between the study groups for either vaccine formulation up to 18 months of age. In this study, we report that a single priming dose of PCV10 or PCV13 (1 + 1 schedule) results in pneumococcal colonization prevalence similar to that of the 2 + 1 schedule through to five years of age. There was no evidence in this study to indicate that a reduced 1 + 1 dosing schedule will increase vaccine serotype colonization in children up to five years of age. These results, when considered alongside existing immunological data, support the UK’s modeling, suggesting that transitioning from a 2 + 1 to 1 + 1 PCV immunization schedule is unlikely to increase breakthrough cases of VT pneumococcal disease in older children, even in settings with residual PCV13 serotype carriage.