The Indian coronavirus variant may not be as transmissible as initially feared, a leading scientific adviser said.
Prof Neil Ferguson – the Imperial College London scientist whose modelling convinced the government to impose the first national lockdown last spring – said there was a “glimmer of hope” that although the variant of concern appears to have a significant advantage over the Kent variant, the “magnitude” of that could be lower than initially thought.
On Tuesday, Boris Johnson insisted there was no “conclusive” evidence to deviate from the road map out of England's lockdown despite the spread of COVID-19 cases involving the B.1.617.2 variant.
The prime minister had last week warned the rise in cases could risk the next stage of England’s road map out of lockdown, currently pencilled in for 21 June, being delayed.
If outbreaks are limited, ministers could opt instead to push ahead with the reopening while keeping some areas under restrictions in an echo of the controversial tiers system introduced last autumn.
On Wednesday, however, Prof Ferguson, who advises the government, said the most recent data suggest the variant may not be as transmissible as feared.
Watch: COVID-19 - Vaccine surge in coronavirus hotspots may not stop Indian variant spread, scientists warn PM
He told BBC Radio 4's Today programme: “We’re trying to work out if the rapid growth we’ve seen in areas such as Bolton is going to be typical of what we could expect to see elsewhere, or if it is what’s called a 'founder effect' – which is often seen in these circumstances.
"There’s a glimmer of hope from the recent data that while this variant does still appear to have a significant growth advantage, the magnitude of that advantage seems to have dropped a little bit with the most recent data so the curves are flattening a little."
But he stressed it will take “a little more time before we can be definitive about that”.
One of the issues facing scientists trying to work out whether this new variant is more transmissible than the Kent version is because of how it entered the UK.
Prof Ferguson said it was introduced from overseas, principally into people with Indian ethnicity, which means there is a higher chance of it being located in multi-generational households and often in quite deprived areas with high-density housing.
He also said it remained unclear whether the vaccine would prevent high levels of transmission in the community.
On vaccines, he emphasised the likelihood of jabs still being able to prevent severe disease – though there were also some “hints in the data” of reduced vaccine efficacy when it comes to getting infected in the first place, and against transmission.
The new strain was designated a “variant of concern” last week. Initially data suggested it could be as much as “50% more transmissible” than the Kent strain, according to the Scientific Advisory Group for Emergencies (Sage).
Prof Ferguson said it is "much easier to deal with 20%, even 30%" than it would be 50% or more.
Last week, England's chief medical officer Prof Chris Whitty said it would only be a matter of time before the new variant became the dominant strain in the UK.
The latest figures, announced by Matt Hancock in the House of Commons on Monday, showed there were 2,323 B.1.617.2 infections in the UK. This was nearly double the number – 1,313 – announced by Public Health England on Thursday.
Watch: What UK government COVID-19 support is available?