By Adam Vaughan
A health worker gives a woman a sample.
Frenchman Philippe Croset is pictured.
There has been a recent surge in cases in South Africa due to a new variant of the disease.
When was B. 1.1.529 first identified?
It was first detected in South Africa on November 23. South Africa's health minister said yesterday that he believes the variant is behind an increase in covid-19 cases across the country. Travel restrictions were imposed for people from South Africa and other countries who were travelling to the UK from yesterday. The World Health Organization lists B. 1.1.529 as a variant under monitoring, but is expected to be elevated to a variant of interest after a meeting of its Technical Advisory Group on the evolution of the disease. The Greek letter "Nu" will probably be its name.
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 and the rate of growth has been fast. The majority of South Africa's cases are in the province of Gauteng. The variant was identified in 77 cases in the province between 12 and 20 November. The average number of people one person will likelyinfecting is 1.5 in the country, but almost 2 in the province of Gauteng.
What do B. 1.1.529's changes tell us?
Sharon Peacock at the University of Cambridge says that the variant has a very unusual constellation of mutations. 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 Alpha and Delta variant have the same furin cleavage site as the one that is changed on the virus. B. 1.1.529 has greater transmissibility than Delta, according to Barclay.
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. In the UK, about a fifth of positive cases are sent for genetic testing. Even in countries with low levels of sequencing, there may be some early warning signs, as the variant is linked to S-gene dropout which is picked up by a test.
How have other countries responded?
The UK and EU have both imposed restrictions on people travelling from countries in southern Africa.
Is it a foregone conclusion that this will beat Delta?
We don't know. There are hints that it may be, but we don't have conclusive evidence at the moment. Alpha spread from Europe but never reached high levels in South Africa because of the competition from other variant, which failed to get a toehold in certain countries. If this variant is not transmissible, that would be good news.
What can I do?
All the usual measures of social distance, hand washing, mask-wearing, getting vaccinations and having a booster are still applied. It is a reminder of the risk of a global vaccine shortage, and why helping low and middle income countries access vaccines is important.
How much do we know about this variant?
The South African government and the Network for Genomic Surveillance in South Africa have been praised by researchers for acting fast to share information on the variant. There is still 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.
There are more on these topics.
