A new Coronavirus mutation, first found in India, has now been discovered in the UK.
Health officials say it has genetic changes that mean it might be more contagious than other strains – and past infection or current vaccines may not offer protection.
But more studies are needed to be sure.
What do we know about the Indian variant?
There are many thousands of different versions, or variants, of Covid circulating – including the Brazilian, South African and UK “variants of concern”.
There is not enough data yet to say the Indian variant is of similar concern.
“To escalate [the Indian variant] up the ranking we need to know that it is increased transmissibility, increased severity or vaccine evading, and we just don’t have that yet,” says Dr Susan Hopkins of Public Health England (PHE).
More than 100 cases of the Indian variant (also known as B.1.617) have been confirmed in the UK.
PHE says it appears a few of the cases are not linked to international travel and investigations into how they were acquired are continuing.
What about the UK, Brazilian and South African variants?
It’s not unexpected that new variants have developed. All viruses mutate as they make copies of themselves to spread and thrive.
Most of these differences are inconsequential. A few can even be harmful to the virus’s survival. But some can make it more infectious or threatening.
Are the new variants more dangerous?
There is no evidence that any of them cause much more serious illness for the vast majority of people who become infected.
As with the original version, the risk is highest for people who are elderly or have significant underlying health conditions.
To prevent infection, it’s important to be extra vigilant about washing your hands, keeping your distance from other people and wearing a face covering.
How do the new variants mutate?
The UK, South Africa, Brazil and Indian variants have all undergone changes to their spike protein – the part of the virus which attaches to human cells.
They all share a mutation, called N501Y, which seems to make the virus better at infecting cells and spreading.
Experts think the UK/Kent strain may be up to 70% more transmissible or infectious – although research by Public Health England puts it between 30% and 50%.
The South Africa and Brazil variants have more potentially important changes in the spike protein.
They have a key mutation, called E484K, that may help the virus evade parts of the body’s immune system. It means patients who’ve previously had Covid, or been vaccinated, can’t rely on the antibodies in their immune systems to fight the mutated virus.
Experts recently found a small number of cases of the UK variant that have this change too.
We already know the Indian variant has some potentially important mutations (E484Q L452R and P681R).
They may affect how well the immune system can fight off the infection, experts suspect.
Will vaccines still work against variants?
Current vaccines were designed around earlier versions of coronavirus, but scientists believe they should still work, although perhaps not quite as well.
A recent study suggests the Brazilian variant may be resisting antibodies in people who’ve already had Covid and should have some immunity.
Data from the Oxford-AstraZeneca vaccine team suggests it protects just as well against the new UK variant.
It offers less protection against the South Africa variant – but should still protect against severe illness.
Early results suggest the Moderna vaccine is effective against the South Africa variant, although the immune response may not be as strong or long-lasting.
Experts say with a new virus mutation, even in a worst case scenario, vaccines could be redesigned and tweaked in weeks or months to be better matches.
The UK Government has announced a deal with biopharmaceutical company CureVac to develop vaccines against future variants, with a 50 million dose pre-order.