Technologies for strengthening immunization coverage in India: a systematic review.

Background: Immunization coverage varies across India in different settings, geographic areas and populations. Technologies for improving immunization access can reduce disparities in coverage. This systematic review, which follows PRISMA guidelines, aims to examine the technologies for strengthening immunization coverage in India. Methods: Studies published between January 1, 2011 and July 31, 2021 were searched in Medline (through PubMed), Cochrane Library and Google Scholar. All observational and experimental studies, except qualitative studies, were included. Studies published in the English language and related to technologies for strengthening immunization, conducted on children, pregnant women, adults, elderly, healthcare personnel, caregivers and vulnerable populations across all Indian settings were included. Non-English articles, protocols, commentaries, letters, abstracts, correspondence, opinion articles, modelling, narrative and systematic reviews were excluded. Two reviewers screened studies independently, extracted data in a standardized sheet and appraised the study quality using the Mixed Methods Appraisal Tool. The primary outcome was technologies that improved immunization coverage. The protocol is registered with OSF (https://osf.io/r42gm). Findings: 6592 titles and abstracts were screened, and data extracted from 23 India-specific studies. Quality of 22/23 studies was average or above. Technologies identified included reminder systems, capacity building, community engagement and wearable technologies. Automated incentivised mobile phone reminders, immunization due-list, computerized data tracking, community mobilization and campaigns improved vaccine coverage, although effectiveness of some varied viz., reminder systems, and across states. Newer technologies included the Jyotigram Yojana, Digital Near-field Communication Pendants, "Reaching Every District" Programme and the "My Village My Home" tool. Interpretation: Technologies for improving immunization systems, capacity building and community engagement were effective. Newer technologies on vaccine delivery, mapping and cold chain logistics were not evaluated in India or were ineffective. There were limited studies in populations other than children and pregnant women. Future work is needed to evaluate the effectiveness of identified technologies across diverse settings. Funding: No funding was received for preparing this manuscript.