Journal Article

Pneumococcal carriage following PCV13 delivered as one primary and one booster dose (1 + 1) compared to two primary doses and a booster (2 + 1) in UK infants

Litt, David J., Goldblatt, David, Southern, Jo, Plested, Emma, Fry, Norman K., Andrews, Nick J., Robinson, Hannah, Miller, Elizabeth, Snape, Matthew D., Aley, Parvinder K., Sheppard, Carmen L., Rose, Samuel, Roalfe, Lucy, Pearce, Emma, Johnson, Marina, Waight, Pauline

2023

Overview

In January 2020 the UK changed from a 2 + 1 schedule for 13-valent pneumococcal conjugate vaccine (PCV13) to a 1 + 1 schedule (doses at 3 and 12 months) based on a randomized immunogenicity trial comparing the two schedules. Carriage prevalence measured at the time of booster and 6 months later in 191 of the 213 study infants was 57 % (109/191) and 60 % (114/190) respectively. There were eight episodes of vaccine-type (VT) or vaccine-related 6C carriage in the 2 + 1 and six in the 1 + 1 group; ≥4-fold rises in serotype-specific IgG in 71 children with paired post-booster and follow up blood samples at 21–33 months of age were found in 20 % (7/35) of the 2 + 1 and 15 % (6/41) of the 1 + 1 group. VTs identified in carriage and inferred from serology were similar comprising 3, 19A and 19F. Dropping a priming dose from the 2 + 1 PCV 13 schedule did not increase VT carriage in the study cohort. Ongoing population level carriage studies will be important to confirm this.

• Publisher: Elsevier Ltd,Elsevier Limited
• Subject: Allergy and Immunology / Antibodies / Antibodies, Bacterial / Child / Conjugate / Humans / Immunization Schedule / Immunogenicity / Immunoglobulin G / Infant / Infants / Nasopharynx / Pneumococcal Infections - epidemiology / Pneumococcal Infections - prevention & control / Pneumococcal Vaccines / Population studies / Priming / Public health / Schedules / Serology / Streptococcus infections / Streptococcus pneumoniae / Testing laboratories / United Kingdom - epidemiology / Vaccine Pneumococcal / Vaccines / Vaccines, Conjugate