By Adam Vaughan
A woman in South Africa gets a sample from a health worker.
Frenchman Philippe Croset is pictured.
A new variant of the disease, known as omicron, has a high number of defects and appears to have caused a surge in cases in South Africa.
When was omicron first identified?
It was first detected in South Africa on November 23. The variant is believed to be behind a daily rise in covid-19 cases in South Africa. The UK Health Security Agency designated it a variant under investigation, triggering travel restrictions for people travelling to the UK from South Africa. The World Health Organization had listed B. 1.1.529 as a variant under monitoring, but the Technical Advisory Group decided on 26 November that it was a variant of concern. The WHO named it after the Greek letter.
What is happening in South Africa?
The national daily cases went from 27 on 11 November to 1000 a fortnight later. The UK saw 50,000 cases on November 26th, but the rate of growth has been fast. The majority of South Africa's cases are in the province of Gauteng. The 77 cases that were identified as being caused by the variant were all in the province. The average number of people that an individual is likely to transmit is less than in the province.
What do B. 1.1.529's changes tell us?
The variant has a very unusual constellation of changes. There are more than 30 changes in the spikeProtein, the part of the virus that interacts with human cells. The virus may be more transmissible and less susceptible to treatments if there are other mutations. The body notes that this has not been proven.
The experience of past SARS-CoV-2 mutations is what determines what the theoretical mean is. Wendy Barclay at Imperial College London doesn't know if it will affect the effectiveness of vaccines. She says that the number of changes across the antigenic sites on the variant's spike means the effectiveness of the covid-19 vaccines would be compromised.
The furin cleavage site is a part of the virus that is similar to those seen in the alpha and delta variant, which could help the variant spread more easily. B. 1.1.529 has greater transmissibility than Delta.
The new variant is likely to be more resistant to treatments such as those developed by Regeneron, which have been shown to save lives. That is a cause for concern. There are no signs that the variant causes more severe disease.
How far has it traveled?
The variant has been found in South Africa. There are cases in Israel and Belgium that are said to be from travellers from Egypt. UK health secretary Sajid Javid said it is likely that the variant has spread to other countries. Two cases have been detected in the UK, where about a fifth of positive cases are sent for genetic testing. Even in countries with low levels of sequencing, it is possible to get early warning signs because of the variant that is linked to the S-gene dropout.
How have other places responded?
The UK and EU have both imposed restrictions on people travelling from countries in southern Africa. Boris Johnson announced travel restrictions on November 27.
Is it a foregone conclusion that this will beat the delta variant?
We don't know. There are hints that it may be, but we don't have conclusive evidence at the moment. In the UK, for example, alpha spread from Europe but never reached high levels in South Africa, because of the competition from other variants. It would be good news if this variant is not transmissible.
What can I do?
All of the usual measures of social distance, hand washing, mask-wearing, getting vaccinations and having a booster shot still apply. Only 24 per cent of people in South Africa are fully vaccineed, which is a reminder of the risk of a different vaccine rate in different parts of the world.
How much do we know about this variant?
Most of our knowledge is from the South African government and the Network for Genomic Surveillance, both of which have been praised by researchers for acting fast to share information on the variant. There is more we don't know. The full significance of the variant's mutations remains uncertain, according to a statement by a professor at a South African university. It is important to stress how little we know about this new variant.
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