Update: 19 December
Evidence is accumulating that the new coronavirus variant may spread more easily than other variants. The Government is introducing extra restrictions to reduce the spread and scientists are continuing to investigate.
On Monday, Secretary of State for Health and Care Matt Hancock mentioned a ‘new variant’ of the coronavirus was circulating in the population of the UK, particularly in London and the South East. He suggested that this new variant may be responsible for the increase in numbers of people who’ve been tested positive for coronavirus recently. But what is the scientific evidence, and what does this mean for the vaccine?
Like all other viruses, the one that causes coronavirus, SARSCoV2, has random changes to its genetic code every so often. These are called mutations and are copying errors that happen when the virus duplicates, with each copying error leading to a new variant of the virus. Most of these copying errors don’t really matter – they don’t change the structure of the virus or change it so little that it doesn’t affect the severity of illness or how contagious the virus is.
Luckily, these copying errors happen less often for coronaviruses than some other viruses, such as those that cause flu. Nevertheless, there are many variants of SARSCoV2 circulating around the world, with different variants more common in different places.
What is new about the new variant?
A group of scientists called COG UK – the COVID-19 Genomics UK Consortium – are monitoring which variants are common in the UK, and whether any of these are becoming more or less common. They’ve noticed that this new variant is becoming more common in London and the South East of England.
The new variant has some mutations to the spike protein of the coronavirus, which change its structure a little.
Does the new variant spread quicker than the old one?
The change in the spike protein in the new variant is to the part of the protein that helps it access the cells in our bodies, which it needs to do to replicate and spread. It is possible that the change makes it easier for the new variant to access our cells, in which case it may be able to spread more easily, but there’s no evidence of this yet.
COG UK have found that, in London and the South East of England, there are increasing numbers of people with the new strain. However, there are increasing numbers of people with coronavirus in the region overall. It’s difficult to work out whether the new variant is spreading because coronavirus in general is spreading, or because there’s something ‘special’ about it. It will take scientists some time to work this out.
Will the vaccine work differently for the new variant?
The spike protein is the part of the coronavirus that vaccines target to stimulate an immune response. However, scientists think that change to the spike protein is not critical here and that the vaccines, including the Pfizer BioNTech vaccine which is currently being given to people in the UK, will work just as well for the new variant. This is because the vaccines train our immune systems to target all parts of the spike protein, including those parts that are unchanged in the new variant. It will be possible for scientists to check this soon.
If coronavirus variants were to emerge which the vaccine worked less well for, vaccines can be modified to maximise the protection they offer. This is what happens with the flu vaccine each year.
Does the new variant cause worse disease?
There’s nothing to suggest that the new variant causes more severe illness than the more common variant. However, this is always a possibility with new variants and that’s why it’s important that their emergence and spread is monitored carefully.
More articles by Dr Webb
Dr Elizabeth Webb is Head of Research at Age UK. She has an MSc in Epidemiology from the London School of Hygiene and Tropical Medicine and a PhD in Social Epidemiology from University College London.