Reactive vaccination of workplaces and schools against COVID-19

As vaccination against COVID-19 stalls in some countries, increased accessibility and more adaptive approaches may be useful to keep the epidemic under control. Here, we study the impact of reactive vaccination targeting schools and workplaces where cases are detected, with an agent-based model accounting for COVID-19 natural history, vaccine characteristics, individuals’ demography and behaviour and social distancing. At an equal number of doses reactive vaccination produces a higher reduction in cases compared with non-reactive strategies, in the majority of scenarios. However, at high initial vaccination coverage or low incidence, few people are found to vaccinate around cases, thus the reactive strategy may be less effective than non-reactive strategies with moderate/high vaccination pace. In case of flare-ups, reactive vaccination could hinder spread if it is implemented quickly, is supported by enhanced test-trace-isolate and triggers an increased vaccine uptake. These results provide key information to plan an adaptive vaccination deployment.