Sometimes the answer to a particular part of a complex problem is simple and obvious. The way to protect particularly vulnerable people, such as those without secure accommodation and at risk in a number of different ways, is to provide them with a place to live and the interventions they need to keep them safe. This was the route taken early in the pandemic. The cocoon metaphor described a particular instance of the Housing First approach, and conveyed a sense of care, protection, and attention at the heart of the response to the needs of people who were homeless and use drugs, particularly in urban areas.

This was an emergency and a literally life-saving intervention. A long-term response will involve a much greater integration of services, careful planning, and consideration of novel approaches. The recent Health Research Board evidence review on treatment services for people who are homeless and use drugs found that failure often stems from the service providers not recognising the breadth and complexity of individual needs. Success depends not only on selecting interventions that are supported by evidence, but also by ensuring that this support is given in a non-judgemental and compassionate way. The service user’s preferences and support from peers need to form part of how the service is delivered if positive outcomes are to be achieved. Sometimes we need scientific support to help us appreciate what we know intuitively to be good and valuable.

In every facet the pandemic is complex. The virus has proved resilient and dangerously mutable. But the response too is complex and adapts and changes as our knowledge of the virus and its transmissibility develops. Health systems design new preventive measures and discover effective treatments in the most trying environments. Patience, generosity, and vigilance have been the defining features of the public response. Social behaviours are not constant but change according to need. Throughout this period, we have learned the importance of careful analysis, the need to integrate insights from the medical and behavioural sciences, and to question easy answers. It may be a lesson we can apply in dealing with more intractable societal problems.