Vaccination programs combined with physical distance could contain COVID-19 resurgence

A combination of robust vaccination programs and strict physical distancing rules could prevent recurring spikes in COVID-19 without the need to rely on stay-at-home restrictions, according to a new study by epidemiologists and demographers from WorldPop at the University of Southampton, in collaboration with the Chinese University of Hong Kong.

This research used anonymized cell phone geolocation data with epidemiological data and coronavirus cases in China to model the potential impact of vaccination and physical distance on virus transmission. They predicted the effect of different combinations of interventions on low, medium and high density cities in the country.

The impact of physical distance on controlling future outbreaks of COVID-19 depends greatly on the intensity of the measures, the density of the population and the availability of vaccines in geographic areas and over time. The researchers sought to better understand the relationship between these factors.

The results are published in the journal Human behavior of nature.

The team predicts that in most cities, vaccination programs and physical distancing combined will be enough to contain the resurgence of the virus without the need to significantly restrict population mobility. Containment in this study was defined as maintaining a low rate of transmission, or “R” below one.

Researchers report that medium and high density cities will need both vaccination and distance to avoid future intense waves of COVID-19, until herd immunity is achieved. However, they suggest that cities with small populations and effective vaccination could interrupt transmission completely without the need for physical distancing. In all cities, full “home” lockouts would no longer be necessary.

The team’s results also suggest that strong physical distancing interventions implemented for short periods of time may be more effective than light interventions over the longer term.

Author and spatial epidemiologist, Dr Shengjie Lai, Senior Researcher in Geography and Environmental Sciences at the University of Southampton comments: “Our research provides a framework and a set of results that can be used by policy makers and decision makers. public health authorities to identify intervention levels to control COVID-19 outbreaks over time. Although our study is based on data from China, our methods and results are applicable to cities around the world with similar levels of population density and patterns of social contact. “

WorldPop Director Professor Andy Tatem added: “Previous studies have assumed that when people reduce their mobility, they proportionately reduce their social contacts, but this is not necessarily the case and as more and more people do. as more SARS-CoV-2 vaccines come online, there is an urgent need to understand the relationship between these factors, so that we can adjust and adapt interventions and open up sections of society in a more safe. “

The researchers recognize some limitations to their study, for example, the lack of data on the contribution of handwashing and face masks and the challenges of vaccine supply, but point out that their approach can be quickly adapted to provide near real-time data to respond to emerging issues, time-critical needs.