Introduction: Despite increased attention to integrated health services, the evidence remains scattered. Several reviews have examined the impact of combining vaccines with other health services, but they usually focus on specific life stages (such as infancy or childhood) (Shah et al., 2024), particular vaccines (like measles or HPV) (Wirtz et al., 2024), or specific health services (e.g., HIV and noncommunicable disease) (Murphy et al., 2025). To date, there has not yet been a comprehensive synthesis of empirical studies that evaluates the real-world effectiveness of integration strategies for vaccination uptake across the life-course stages in LMICs. This review addresses this gap. The primary research questions is: when, where and how have vaccines been integrated into existing health services platforms in LMICs?
Method: Studies were identified through PubMed and Ovid MEDLINE databases. The search was also supplemented with grey literature identified through consultations with experts recommended by UNICEF. Inclusion criteria include primary empirical research studies (including mixed-method, experimental, quasi-experimetal and qualitative designs) conducted in LMICs that report a vaccine-related outcome. Exclusion criteria include systematic reviews, scoping reviews, protocols, policy briefs, studies not conducted in LMICs, and studies not published in English.
The systematic review is ongoing and expected to be completed by the end of the year. Preliminary analysis of the (85 out of 121) included studies reveals that immunization integration in LMICs is not a single model but is best seen as a continuum rather than two binary options between integrated vs. not-integrated. At the lower end of the spectrum, integration simply means vaccination and other health services are offered as referrals or on different days ( or different locations on the same day), leaving the patients to seek the additional service. A more common and practical approach is the co-delivery of multiple services at the same location during a single visit.
For instance, administering Vitamin A supplements during Polio days. The deepest level of integration occurs when vaccination is fully embedded into another service’s workflow and structure. For eg, all children visiting for nutrition or curative services may first be screened for vaccination status, with zero-dose or under-immunised children being directed to vaccinators before accessing other services. Here, immunisation is not just an add-on but a required, built-in step.
Immunization most frequently occurs with maternal and child health (MCH) services, including antenatal and postnatal care, while the HPV vaccine is often linked with Cervical cancer screening. Three main platforms are used to deliver integrated services: i) community-based platforms (e.g., mobile clinics, outreach, and home visits) are the most common to overcome access barriers for remote populations, ii) primary care facilities leverage existing infrastructure and routine patient visits to efficiently deliver multiple services, iii) school-based delivery.
Conclusion: Successful programs seem to invest in their training that goes beyond technical skills to include important “soft skills” such as culturally sensitive counseling and interpersonal communication. The healthworkers are also provided with financial (e,g., per diems) and/or non-financial incentives (such as recognition for their work, seeing positive impact on community health).
