The relevance of travel behaviour in the SARS-CoV-2 spread

We are  to share the results of our latest Nature paper “Spread of a SARS-CoV-2 variant through Europe in the summer of 2020”, an international collaboration with the University of Basel, the SeqCOVID-SPAIN consortium, and other amazing institutions in Switzerland, Spain and US.

Before the UK, Brazilian or Indian variants, there was a precedent last summer that put researchers as Dr Emma Hodcroft and her colleagues in alarm: a recently detected variant of SARS-CoV-2 (EU1) with a mutation in the spike protein was spreading faster than any other else along Europe. Early testing performed by Prof Iñaki Comas and Prof Fernando González Candelas helped to identify its origin in Spain in June 2020.

Fortunately, laboratory tests showed that the mutation in the spike did not grant a significant increase in the transmission or change in the antibody binding. So this result raised a question: how was this variant so successful all along Europe if there was no intrinsic difference in the virus?

Our data on international mobility between Spain and all European countries (the same we use for monitoring the tourism in any location in Spain) helped to build a model to correlate mobility with incidence estimates and created a map of how this variant emerged in Spain and spread to all the other countries: not all nationalities visit the same places or behave in the same way when they spend their holidays in Spain, and these differences are key to understand the incidence measured in the countries of residence. It also reflects the different policies taken by those countries with respect to quarantines or testing, and how relaxed strategies opened the door for larger incidences.

COVID visitors.png

In conclusion, we see how the intrinsic transmission property of the virus is not the only factor that makes a variant more successful over the others, but also our own behaviour and travel patterns. Vaccination is a key differentiator for travelling in summer 2021, but we should keep tracking the evolution of the new variants and how they use our same airplanes and highways to move from one region to another!

This study also shows the relevant role of Spain regarding international tourism, being one of the major destinations in Europe and around the globe. Whatever happens in Spain will have its echo in the World! We really believe that data is the tool we need to understand the challenges that we will face in the post-COVID era.

Please follow Emma’s thread for more details on this research and her amazing work!

Advanced Big Data & Machine Learning

Explore the science of Social Physics & big data