Inequalities in childhood pneumococcal conjugate vaccine uptake in England before and after the change from a 2+1 to 1+1 schedule: a longitudinal study

BackgroundIntroducing the pneumococcal conjugate vaccines (PCV) into the routine childhood immunisation schedule in England has reduced pneumococcal disease burden. Nonetheless, pneumococcal disease continues to a]lict marked morbidity and mortality in the population, including young children. In January 2020, England transitioned from a "2+1" PCV schedule (two primary doses at 8 and 16 weeks, with a booster dose at 12 months) to a "1+1" PCV schedule (single primary dose at 12 weeks and a booster dose at 12 months). While immunogenicity studies suggested comparable protection, reducing primary vaccine doses places greater emphasis on timely booster uptake. MethodsWe examine national trends in PCV uptake before and after the schedule change and quantify inequalities by deprivation. We analysed quarterly vaccine uptake data for 2013-2025 from the Cover of Vaccination Evaluated Rapidly (COVER) programme for upper-tier local authorities in England linked to 2019 Index of Multiple Deprivation quintiles. We examined booster gaps - the di]erence between primary coverage at 12 months and booster coverage at 24 months. We estimated susceptibility to pneumococcal disease (by birth cohort stratified by quarter) by combining observed PCV uptake with published vaccine e]ectiveness estimates. FindingsBooster retention deteriorated following the schedule change; mean booster gaps increased from 2.32% (2+1 period) to 4.79% (1+1 period). The largest booster gaps arose in London boroughs. The gap between least and most deprived quintiles widened from 2-3% (2+1 period) to 4-6% (1+1 period). Susceptibility calculations returned notable geographical variation in estimated vaccine type invasive pneumococcal disease susceptibility in England, with disproportionate burden in deprived areas. InterpretationsThe success of the 1+1 schedule depends on maintaining equitable, high booster uptake. Declining booster retention and widening inequalities threaten programme e]ectiveness. Increased resource allocation for child immunisations, strengthened follow-up systems and targeted interventions in deprived communities are essential to prevent widening protection gaps. FundingNo specific funding for this project. Research in contextO_ST_ABSEvidence before this studyC_ST_ABSPneumococcal conjugate vaccines (PCVs) have been part of the routine childhood immunisation schedule in England since September 2006, firstly using PCV7 (targeting seven serotypes) and then from 2010 PCV13 (targeting thirteen serotypes). This has resulted in reduced invasive pneumococcal disease (IPD) burden, although IPD continues to cause marked morbidity and mortality across the population, including young children. Originally administered as a "2+1" schedule (two primary doses at 8 and 16 weeks, with a booster dose at 12 months), England transitioned In January 2020 to a "1+1" PCV schedule (single primary dose at 12 weeks and a booster dose at 12 months). While immunogenicity studies suggested comparable protection, reducing primary vaccine doses places greater emphasis on timely booster uptake. We searched PubMed, Google Scholar, and medRxiv for articles published in English from inception to 30 Nov 2025 with the following search terms: ("PCV-13" OR "13-valent pneumococcal conjugate vaccine" OR "pneumococcal conjugate vaccine") AND (booster OR "third dose" OR "2+1 schedule" OR "additional dose") AND (children OR infants OR toddlers OR paediatric OR paediatric) AND ("vaccine e]ectiveness" OR "vaccine e]icacy") AND "England". To our knowledge, an observational analysis investigating potential inequalities in Childhood Pneumococcal Conjugate Vaccine Uptake and resultant susceptibility to IPD in England Before and After the change from a 2+1 to 1+1 schedule in January 2020 has not been conducted. Added value of this studyWe analysed temporal and spatial trends and inequalities in PCV13 uptake across England at an Upper Tier Local Authority level for 2013-2025. This period included the January 2020 transition from a 2+1 to 1+1 dose schedule. The analysis revealed three critical findings: booster retention deteriorated under the 1+1 schedule; socioeconomic inequalities in vaccine uptake persisted and widened (particularly a]ecting the most deprived communities); using a susceptibility calculation that combined PCV uptake data with current knowledge on vaccine e]ectiveness estimates for PCV13 against vaccine type IPD, we highlight a growing inequitable susceptibility to vaccine type IPD in child cohorts. Implications of all the available evidenceOur study shows that PCV booster retention has notably declined in England since the change from a 2+1 to a 1+1 schedule change. This means the full protective potential of the 1+1 schedule is not being realised. A trend of lower booster retention amongst children in more deprived areas risks avoidable disease burden being concentrated in the most disadvantaged communities and widening health inequalities. Other countries considering a 1+1 schedule change should consider underlying inequality in vaccine uptake and booster retention before implementation. Systems strengthening and targeted, equity-focused interventions are needed to address the identified coverage gaps.