A study of COVID-19 transmission dynamics in Canada illustrates the role of travel restrictions in buying time to scale up testing, tracing and healthcare interventions.
A study of COVID-19 variant transmission into and across Canada shows that international travel restrictions were a key intervention for reducing or slowing spread, according to a report published today in eLife.
The results suggest that reducing the number of virus importations that can spark domestic outbreaks within a country through dynamic travel bans allows governments more time to prepare for a new variant – by ramping up testing, contact tracing and vaccination programmes.
The COVID-19 pandemic has highlighted the importance of genomic epidemiology – that is, genetic sequencing of SARS-CoV-2 samples from different regions and times – to understand the origin and movement of virus variants internationally, especially variants of concern or interest. These methods have been used widely in the UK, US, Brazil, New Zealand and Europe, and have illustrated the variation in epidemic dynamics between countries that took different public health approaches to containing the virus.
“Large-scale SARS-CoV-2 genomic epidemiology analyses in Canada have so far been limited to a study on the early epidemic within Quebec,” says lead author Angela McLaughlin, Research Assistant at the British Columbia Centre for Excellence in HIV/AIDS, and a PhD candidate in Bioinformatics, University of British Columbia, Canada. “We wanted to elaborate on this research with a national-scale analysis for the first and second COVID-19 waves. We also wanted to evaluate the impact of international travel restrictions in March 2020 on international importations of the virus and to understand why the virus persisted into 2021.”