The global pandemic has brought renewed attention toward the everyday challenges in informal settlements. COVID-19 reminds us that southern urban life is rooted in ‘collective’ experiences where toilets and kitchens are shared by multiple families; where the categories of work and home, private and public space overlap; and where the majority live in vulnerable conditions. Despite these challenges, some of the most innovative and collective responses to COVID-19 have emerged from these areas. While informal settlements did face a host of risks and vulnerabilities during the pandemic, local responses have highlighted the resilience of informal settlement communities. However, few informal settlements are actually ‘resilient’ and any local responses must be robustly supported by system-wide change including support from local and national governments, improvements to built infrastructure, and improved access to health care services, among other priorities. The category of ‘informal settlements’ also captures a wide range of settlement types, from a legal slum to an informal settlement with no legal status, with many other types in between. This underscores the need to address fundamental issues that ‘perpetuate conditions of inequity, exclusion and vulnerability’ while also recognising the needs and contexts of different kinds of informal settlements. Whether COVID-19 helps governments recognise conditions of insecurity and vulnerability to address safe and secure housing and infrastructures remains to be seen. This is an update to the previous SSHAP brief on ‘COVID-19 in Informal Urban Settlements’ (March 2020). This evidence review highlights local responses, grassroots efforts, and challenges around COVID-19 recovery within urban informal settlements in South Asia. It focuses on specific examples from Karachi, Pakistan and Mumbai, India to inform policy responses for COVID-19 recovery and future epidemic preparedness and response. We show how local level responses are shaped in these cities where national and international responses have not reached communities at municipal and sub-municipal levels. This brief was written by Saba Aslam (IDS Alumni) and Megan Schmidt-Sane (IDS), with reviews from Professor Amita Bhide (Tata Institute of Social Sciences, India), Dr Asad Sayeed (Collective for Social Science Research, Pakistan), Annie Wilkinson (IDS), and contributions from Swati Mishra (LSHTM), Prerana Somani (LSHTM), Saleemullah Odho (Deputy Commissioner, Korangi district Karachi), Dr Noman Ahmed (NED University, Karachi), Tahera Hasan (Imkaan Foundation, Karachi), Atif Khan (District Health Officer, Korangi district Karachi), Dr Harris (District Focal person, Korangi), Aneeta Pasha (Interactive for Research and Development, Karachi), Yasmeen Shah (Pakistan Fisherfolk Forum), Ghulam Mustafa (HANDS Pakistan), and Dr Shehrin Shaila Mahmood (icddr,b). This brief is the responsibility of SSHAP.