Private sector engagement for immunisation programmes: a pragmatic scoping review of 25 years of evidence on good practice in low-income and middle-income countries.

Introduction: Many National Immunisation Programmes attempt to leverage the private sector ; however, there is limited consolidated and synthesised documentation on good practices, gaps and lessons learnt. A 2017 WHO guidance document recommended best practices for private sector engagement (PSE) in immunisation. We conducted a pragmatic scoping review to identify gaps, update and consolidate evidence on promising practices in PSE for vaccination.

Methods: Building on two previous reviews published in 2011 and 2017, we conducted a pragmatic scoping review of peer-reviewed publications from low-income and middle-income countries since September 2016 in PubMed that pertained to PSE and immunisation service delivery. We extracted and analysed findings using a new analytical framework covering motivations, enablers and barriers, risks and challenges, and engagement mechanisms.

Results: We collated over 80 well-documented analyses of PSE for vaccination, derived from 54 peer-reviewed publications from 1998 to 2016 included in prior reviews, 21 new publications from 24 countries published since 2016 and 1 new systematic review. The level of PSE was mixed, ranging from 3%-4% to >60% of all childhood vaccinations. Promising practices for PSE included using governance and policy to leverage private providers' motivations and including them in programme efforts. Planning and monitoring efforts were effective when linked with regulatory requirements based on national standards for services, reporting and performance monitoring. Information systems were effective when they included private sector services in vaccine monitoring and surveillance. Challenges identified included ensuring compliance with national schedules and standards and minimising financial exclusion. Few studies documented successful public-private partnership models or other innovative financing models.

Conclusion: The published evidence captures numerous strategies to facilitate stronger immunisation programme engagement with the private sector. Stronger PSE can potentially reach zero-dose and underimmunised populations in low-resource settings and build resilient systems. Untapped opportunities exist for more structured testing of approaches to inform global guidance.