Evaluating the impact of a community-engagement intervention on the uptake of childhood vaccines in England: A synthetic control analysis

ObjectiveTo evaluate the impact of equity-focused community-engagement initiatives on the uptake of five routine childhood vaccinations. DesignQuasi-experimental study within a synthetic control analysis framework. SettingPrimary care in England between April 2019 and March 2025. Childhood vaccination data were obtained from the Cover of Vaccination Evaluated Rapidly (COVER) programme. InterventionThe Health Equity Liverpool Project (HELP) is a community-engagement vaccination initiative implemented between October 2023 and June 2024 across nine sites in central and north Liverpool. Activities were co-developed with local partners and delivered in neighbourhoods with persistently low childhood vaccine coverage. Intervention practices were defined as those located within 1 km of HELP delivery sites (n=19). A weighted combination of non-intervention practices across England (n=5826) was used to construct a synthetic control group. Main outcomesQuarterly counts of vaccinated children following intervention implementation for first doses of the measles, mumps and rubella vaccine (MMR1 at 24 months and at 5 years), second dose of MMR (MMR2 at 5 years), pneumococcal conjugate vaccine (PCV at 24 months), the 6-in-1 vaccine, covering diphtheria, tetanus, pertussis, polio, haemophilus influenzae type b, and hepatitis B (at 12 months), and the rotavirus vaccine (at 12 months). ResultsFollowing HELP, rotavirus vaccine uptake increased by 10.03% (95% CI 0.37% to 24.63%), corresponding to 120 (95% CI 4 to 295) additional infants vaccinated in the intervention group compared to the synthetic control. Similarly, 6-in-1 vaccine uptake rose by 11.56% (95% CI 2.37% to 25.56% [~]143 95% CI 29 to 317 additional children vaccinated. No statistically significant changes were observed for MMR1, MMR2, or PCV. Improvements were short-lived, with uptakes returning to pre-intervention levels after approximately nine months. ConclusionsCommunity-engagement vaccination interventions may produce a modest short-term improvement in uptake of selected early life vaccines but show limited evidence of benefit for MMR uptake. Our findings suggest that such approaches are unlikely to have a sustained impact without long-term investment, integration into existing immunisation systems and addressing the wider social determinants of health. What is already known on this topic?O_LIChildhood vaccination rates in England have declined over the last decade and inequalities in uptake are persistent andwidening. C_LIO_LIChildren in socioeconomically deprived areas are less likely to receive routine vaccinations, reflecting both structural barriers and vaccine hesitancy driven by misinformation and lack of trust. C_LIO_LIInnovative community engagement interventions are recommended to address these inequalities, yet evidence of their effectiveness remains limited. C_LI What this study adds?O_LIOur study shows that hyperlocal community engagement interventions can increase uptake of early-life infant vaccines (rotavirus and 6-in-1) by around 10-12% but provides limited evidence of similar improvements for the MMR vaccine. C_LIO_LIThe observed improvements in infant vaccines were transient, returning to baseline levels after approximately nine months, suggesting that one-off initiatives may not produce sustained public health gains without tackling wider social determinants of health. C_LI