Interventions to improve pre-school vaccination timeliness: a systematic review.

Clinical Snapshot

Key Findings

• P Value: Not reported in abstract

• Effect Size: Not quantified in abstract; directional evidence of potential beneficial effect reported for combination vaccines, communication, quality improvement, education, and schedule change interventions. Call-recall interventions showed no clear beneficial effect signal based on abstract reporting.

• Primary Outcome: Timeliness of pre-school vaccinations (children aged 0–5 years) across seven intervention categories: call-recall (n=10), quality improvement (n=9), education (n=5), multicomponent (n=5), combination vaccines (n=2), communication (n=1), and vaccination schedule change (n=1)

• Nnt Or Sensitivity: Not calculable from available data; no NNT, absolute risk reduction, or relative risk estimates provided in the abstract

• Confidence Interval: Not reported in abstract

Clinical Application

Feasibility varies substantially by intervention type. Quality improvement interventions and vaccination schedule changes require system-level implementation and commissioning decisions. Call-recall systems are already embedded in NHS England's Child Health Information Systems (CHIS) but showed limited evidence of benefit in this review. Education and communication interventions are low-cost and potentially scalable in primary care. Combination vaccine strategies depend on TGA/MHRA-approved formulations and NHS supply chain decisions. This review has moderate indirect relevance to Australian practice. The Australian Immunisation Register (AIR) and the National Immunisation Program (NIP) schedule share structural similarities with the UK schedule. RACGP guidelines emphasise opportunistic vaccination and recall systems analogous to those studied. PBS-listed combination vaccines (e.g., hexavalent vaccines) are already standard in Australia, consistent with the combination vaccine evidence strand in this review. The Australian context differs in its mixed public-private primary care model, which may affect the transferability of quality improvement and call-recall interventions. ATAGI and state health departments would need to consider local vaccination coverage data and equity gaps (particularly for Aboriginal and Torres Strait Islander children) before adopting specific interventions. The finding that call-recall interventions showed limited benefit warrants attention given their prominent role in Australian immunisation catch-up strategies. Children aged 0–5 years receiving scheduled vaccinations in high-income country healthcare settings. Most directly applicable to primary care and community health settings delivering the UK national childhood immunisation schedule, including 8-week, 12-week, 16-week, 1-year, and pre-school booster vaccinations.

Abstract

BACKGROUND: Improving the timeliness of pre-school vaccinations (children aged 0 to 5 years) is an important public health goal to prevent outbreaks and maximise protection during early childhood. Multiple studies have highlighted the need for effective public health interventions to improve timely vaccination, and consequently the overall effectiveness of vaccination programmes. We aim to synthesise evidence on vaccination timeliness interventions and subsequently provide recommendations to improve pre-school vaccination timeliness in England. METHODS: We conducted a systematic review of randomised controlled trials (RCTs) and non-randomised studies. Studies were eligible if they were conducted in high-income countries and evaluated an intervention to improve timeliness of any pre-school vaccination on the United Kingdom (UK) national childhood vaccination schedule. Five databases and grey literature were searched to February 2025. Risk of bias was assessed using Cochrane risk of bias tools. Data were analysed using random-effects meta-analyses and synthesis without meta-analysis (using effect direction plots). RESULTS: Of the 10,385 records from database searches and 1490 records from citation searches, 33 studies were eligible (15 RCTs, 18 non-randomised studies). Most studies were conducted in the USA (n = 24) and reported on the timeliness of multiple pre-school vaccines (n = 23). Twelve studies (36%) were judged as serious or critical risk of bias, eleven at moderate and ten at low risk. Various intervention groups were identified: call-recall (n = 10), quality improvement (n = 9), education (n = 5), multicomponent (n = 5), combination vaccines (n = 2), communication (n = 1) and vaccination schedule change (n = 1). We found limited evidence from a small number of studies of a potential beneficial effect of combination vaccines, communication, quality improvement, education and schedule change interventions. CONCLUSION: We identified several possible interventions to improve pre-school vaccination timeliness. However, we found limited quantity and quality of evidence on this topic. We recommend further high-quality studies evaluating interventions to improve vaccination timeliness in England, and application of consistent vaccination timeliness definitions.

References

1. 1.Sanderson, K., Butt, S., Campbell, C. N. J., Beck, C. R., & French, C. E. (2026). Interventions to improve pre-school vaccination timeliness: a systematic review. Vaccine. https://doi.org/10.1016/j.vaccine.2026.128751