A new variant quickly becoming dominant in South Africa is now under investigation by the UK Health Security Agency. It has not been detected in the UK, but the Government has imposed travel restrictions on six African countries in the hope of preventing its arrival.
The new COVID-19 strain, named B.1.1.529, was identified from samples taken from 14 to 16 November 2021. It was then confirmed in China, after a South African traveller entered the country, and has since been reported to be in Belgium.
The UK Health Secretary Sajid Javid made a statement to the House of Commons on 25 November in which he expressed concern over the spread of B.1.1.529.
“We are concerned that this new variant may pose substantial risk to public health,” said Javid. “Early indications show this variant may be more transmissible than the Delta variant, and current vaccines may be less effective against it.”
Javid also said that mutations found in B.1.1.529 may impact the effectiveness of a major COVID-19 treatment used in hospitals in the UK, called Ronapreve.
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Professor Tulio de Oliveira, a virologist and Director of the Centre for Epidemic Response and Innovation in South Africa, spoke at a briefing on COVID-19 developments that was arranged by the South Africa department of health.
“[The B.1.1.529 variant has a] very unusual constellation of mutations,” said de Oliveira at the briefing. He explained that there are around 50 mutations in the B.1.1.529 genome, 30 of which are in the spike protein. To compare, the Delta variant has 13 mutations.
Of these 30 mutations, some have been well characterised by scientists and have a known impact on transmissibility and the virus’s ability to evade immunity. However, de Oliveira said many of the mutations have been rarely seen before, and so are not fully understood.
The WHO has assigned B.1.1.529 the name Omicron, following the theme of letters of the Greek alphabet.
How many cases of the Omicron variant have been detected in the UK?
So far, there are no known cases of the new B.1.1.529 variant in the UK.
According to data from the GISAID COVID tracking initiative there have 65 cases identified in South Africa. Scientists have also confirmed six cases of the Omicron variant in Botswana, and four in Hong Kong.
Will vaccines still work against the Omicron variant?
There is not yet enough evidence to say conclusively whether the B.1.1.529 variant will be able to evade protection from coronavirus vaccines.
However, at the briefing with South African Minister of Health Dr Joe Phaahla, experts revealed what is known about the new strain.
Mutations to the coronavirus spike protein affect the ability of the virus to enter human cells. Of the 30 mutations found in the B.1.1.529 spike protein, several changes have been identified that are associated with resistance to antibodies from either a COVID-19 vaccine or natural immunity following prior infection.
The Omicron variant also has a deletion to a gene that is similar to one found in Alpha, Beta, Gamma and Lambda, which is thought to strengthen the virus’s ability to evade immune system responses.
Is the Omicron variant more transmissible?
According to Javid, the UK Health Security Agency is worried “about the rise in cases in Southern Africa [because] these populations should have significant natural immunity [from prior infections].” However Javid said we cannot yet be sure that the exponential growth of COVID-19 cases in South Africa is due to B.1.1.529 but that it’s likely there are more cases of the Omicron variant than currently sequenced.
The new strain is known to have mutations near an area on the spike protein associated with more efficient cell entry, which means enhanced transmissibility among populations.
It also has mutations that are known to increase the infectivity, fitness, and virulence of SARS-CoV-2.
How are we tracking the spread of B.1.1.529?
The WHO’s variant under monitoring designation means the WHO will be monitoring and tracking the global spread of B.1.1.529, and will be undertaking its own assessment of the variant’s characteristics and public health risk.
It also means countries that are members of WHO – which the UK is – are required to:
- Work to enhance efforts towards a more representative picture of circulating variants, including making data publicly available
- Perform field investigations to improve understanding of the characteristics of B.1.1.529
- Conduct laboratory investigations to better understand the new variant
- Monitor the spread of B.1.1.529 and its interaction with other circulating variants to asses its potential for outcompeting
What are the symptoms of the B.1.1.529 variant?
As far as we know, this new variant appears to have the same symptoms as all other coronavirus strains. The main symptoms of COVID-19, according to the NHS, are:
- a high temperature – this means you feel hot to touch on your chest or back (you do not need to measure your temperature)
- a new, continuous cough – this means coughing a lot for more than an hour, or three or more coughing episodes in 24 hours (if you usually have a cough, it may be worse than usual)
- a loss or change to your sense of smell or taste – this means you’ve noticed you cannot smell or taste anything, or things smell or taste different to normal
The NHS say that most people who have symptoms of COVID-19 will have at least one of the above.
What other variants have been identified in the UK?
As of 26 November 2021, there are four strains considered to be ‘of concern’ by PHE, including the Delta and Alpha variants.
The PHE are monitoring a total of 15 variants.
BBC Science Focus has contacted PHE for a comment on the spread of B.1.1.529.