The scientists believe holidaymakers returning from Spanish vacations most probably played a prominent role in spreading the strain across Europe and onto the UK.
Although, only in its preliminary stage, Dr Emma Hodcroft, an evolutionary geneticist at the University of Basel and lead author of the study, told BBC Radio 4’s Today programme, “We know there was a super-spreading event among agricultural workers in Spain, that then the virus was able to jump into the local population and start moving more generally around Spain,” she explained.
“This happened in June and July, when travel was picking up again in Europe, and of course Spain’s a wonderful holiday destination and many people headed there. What we think happened is that rising cases in Spain combined with that increase in holiday travel allowed the virus to move to many different countries across Europe and, when it got there, it was able to spread quite successfully.”
The study found that in Wales and Scotland it accounted for about 80% of cases in mid-September, whereas the proportion in England was about 50% at that time.
However, Hodcroft also suggested that there was no actual evidence that the strain spread faster than other strains of coronavirus and neither that the strain causes more severe disease, or would affect how a vaccine works.
She claimed that it was the movement of people during the height of summer rather than the strain being particularly powerful or dangerous, that contributed to its spread across the continent.
Addressing the lessons the UK could learn from the report, Hodcroft said, “I think there were actually three real failures here. So, first, the cases were rising in Spain earlier than in most of Europe, but we still allowed people to travel there.
“On top of that, we didn’t really do much screening of passengers at airports, and it’s very likely that possibly people didn’t follow the quarantine as much as they were supposed to.
“And, finally, if the variant did get back to another European country, those countries weren’t able to cut that off quickly with just a few people, and instead it had a good environment where it could spread more widely, so I think these are all things we could address.”
Hodcroft added, “Certainly, it is associated with the second wave, but we don’t think it’s responsible for it and we really hope we can learn from it the future so that next time, when we start opening up travel again, we won’t have to risk having cases rise again.”