Background and study objectives MHPSS is increasingly seen as a critical component to effective and responsible humanitarian programming. This review examines the extent to which MHPSS research generated since 2010 has contributed to the public health evidence base and how this has influenced and impacted programming and policy in humanitarian settings. Methods This mixed-method study included a scoping literature review (n = 50) and a consultation process with qualitative key informant interviews (n = 19) and online survey responses (n = 52) to identify the facilitating and inhibiting factors for the two areas of inquiry and to understand the broader context in which knowledge is generated and taken up. The interviews were thematically analysed and the survey responses were descriptively analysed. Results The review identified a rapidly growing evidence base that has evaluated a range of MHPSS interventions. However, few studies examined long-term impacts of interventions, there was limited direct evidence on outcomes for children and adolescents and whole family approaches, and there were minimal replications of the same approach that could test efficacy across settings and population groups. A general shift was identified in the consultation process away from a focus on disorder towards the more positive aspects of wellbeing. However, there remained a mismatch in many studies included in the literature review, whereby the interventions were broad, community-based but the outcome measures used still focused on changes in symptoms of mental disorders. Conclusion The evidence base for MHPSS has grown significantly over the last 10 years. However, several knowledge gaps remain, as does the divide between research and practice. Moving forward, MHPSS intervention research needs to be more responsive to the needs on the ground.

Long-term research projects are not always able to adapt to a new crisis and incorporate characteristics and approaches of rapid research to produce useful data quickly. Project AViD was a programme of research that ran between 2018 and 2022 to examine factors that shape vaccine confidence. The project initially focused on five country case studies looking at vaccines for Ebola, Measles, Rift Valley Fever and Zika. The COVID-19 pandemic emerged during this time and provided an opportunity to contribute to the pandemic's ‘million-dollar question'–how to deploy COVID-19 vaccines. Drawing on our experience as researchers, and specifically from AViD, we propose seven factors that can influence when and how longer-term qualitative research projects can adapt and contribute to the response to an unfolding health emergency. These include: (1) the phase of research in which the emergency hits; (2) the relative significance of the emergency in the research setting; (3) the specific methods and research team capacities; (4) existing operational links; (5) supportive ecosystems; (6) flexibility in research contracting and funding; and (7) the research team attitude and approach. We close with two considerations for longer-term research projects that find themselves having to “change gear” amid a public health emergency–the need to re-assess risks and benefits and the need to protect equitable partnerships.