A team of scientists have analysed the first wave of the Covid-19 outbreak.
The highest number of transmission chains during the first half of 2020 were from Spain (33%), with France accounting for 29% of the imports, Italy 12% and China 0.4%.
Researchers from the Universities of Oxford and Edinburgh have analysed the first wave of the Covid-19 outbreak in the UK and produced the most fine-scaled and comprehensive genomic analysis of transmission of any epidemic to date.
This has offered a never-before-seen level of insight into the origins and behaviour of transmission chains since the start of the pandemic.
The full analysis, published today in Science, reveals that high travel volumes and few restrictions on international arrivals before the March 2020 lockdown led to the establishment and co-circulation of more than 1,000 identifiable UK transmission lineages.
The researchers said earlier travel and quarantine interventions could have helped reduce the intensity of the UK’s first wave of cases.
Professor Oliver Pybus, from the University of Oxford’s Department of Zoology and the Oxford Martin School, who is co-lead author on the study, said: “This study shows that it’s possible to trace individual virus transmission lineages accurately through time and space.
“Undertaking analyses on a weekly basis means that genomic tracking can become a key component of public health surveillance.”
Their analysis is based on more than 50,000 genomes, or genetic material, of Sars-Cov-2, the virus that causes Covid-19, that was available before June 2020.
The experts also said their findings offer a crucial context to what is currently happening in the UK’s second wave as a new coronavirus variant, dubbed B.1.1.7 and VUI – 202012/01, continues to rapidly grow across the country.
They believe that a detailed comparison of the new variant’s behaviour with that of coronavirus lineages from the first wave will help understand why B.1.1.7 is spreading so quickly.
Co-lead author Louis du Plessis, a postdoctoral researcher at Oxford’s Department of Zoology, said: “Our work offers unparalleled views into what’s happening in an individual epidemic.
“The UK shares large volumes of virus genetic data publicly on a weekly basis and if you don’t have this level of surveillance you won’t know the real situation of virus evolution and transmission.
The ability to ramp up genomic surveillance at a large scale was made possible by the decision to fund the COVID-19 Genomics UK (COG-UK) consortium in April and builds on decades of blue-skies basic research into virus evolution, led by Oxford and Edinburgh universities, which developed the theory leading to scientists having these tools and theory at their disposal.