This paper reviews the effects of vertical responses to COVID-19 on health systems, services, and people’s access to and use of them in LMICs, where historic and ongoing under-investments heighten vulnerability to a multiplicity of health threats. We use the term ‘vertical response’ to describe decisions, measures and actions taken solely with the purpose of preventing and containing COVID-19, often without adequate consideration of how this affects the wider health system and pre-existing resource constraints.