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Tuesday, January 19, 2021

A few deets about the new South African strain of the Covid virus.

 Daily Mail, along with its inimitable celeb sidebar, publishes helpful, detailed content.

There are world maps on variant strains, and this excerpting:

 

The virus appears to be evolving to transmit around 50 per cent faster and to get past some antibodies made in response to other variants of the virus.

Antibodies are extremely specific, fitting to the virus like a key in a lock, and are moulded to the virus when it is in the body. If the virus changes too much, the old antibodies may no longer be able to fit to it and so can't destroy it. 

This means people infected with the virus three months ago or more may not have total natural immunity if they catch a newer version. 

A study by the University of Washington looked at how the blood of people with antibodies for an older version of coronavirus reacted to the new variant. 

In a group of 11 blood samples, nine of them showed 'reduced binding' from antibodies when exposed to the key mutation on the South African variant.

The mutation they studied is called E484K, which changes the shape of the spike protein that the virus uses to latch onto cells in the body. The same mutation has also been spotted in both Brazilian variants.

[...]

It's likely that there have been far more cases of the variant because the Covid-19 Genomics UK Consortium (COG-UK) only analyses 10 per cent of random positive coronavirus samples. 

COG-UK say they've not found any evidence yet that it will make the current wave of vaccines less potent. 

In their 41-page report, COG-UK said tests had already been carried out on the South African variant which established some of its mutations did not lessen the effectiveness of the vaccine.

But they added that not all of the mutations were checked that are found on the rapidly spreading strains in the UK, South Africa and Brazil. 

In a scientific study published as a pre-print on medRxiv, the scientists describe the genetic make-up and spread of the South African strain.

'This lineage emerged in South Africa after the first epidemic wave in a severely affected metropolitan area, Nelson Mandela Bay, located on the coast of the Eastern Cape Province,' they wrote.

'This lineage spread rapidly, becoming within weeks the dominant lineage in the Eastern Cape and Western Cape Provinces.'

They added: 'While the full significance of the mutations is yet to be determined, the genomic data, showing the rapid displacement of other lineages, suggest that this lineage may be associated with increased transmissibility.' 

It comes after Dr Christina Pagel, who is part of the Independent SAGE group, which has been highly critical of the Government's pandemic response, told The Times: 'We know that this virus does mutate and it mutates in ways that can potentially evade the vaccine.

'Once we start vaccinating, we really want to vaccinate everybody before it starts to have the opportunity to mutate because then you’re much more protected.

The pre-print link shows a host of co-authors, most South African, and kudos to Daily Mail for including the link. 

The bottom line, there are mutations happening, and a mutation of an organism which enhances its reproduction will take off via natural selection.

So, two jabs, (where the second is important as to timing following the first), are needed for vaccines currently approved in the U.S.  

That means vaccine availability and delivery have to be efficient for both jabs. Management of vaccination programs will have its glitches. And the parting sentence in the excerpting - wanting to ideally eradicate the virus by universal vaccination before mutations present further risks - how likely might that, in reality be? There are the anti-vaxxers who basically free-load on herd immunity, and that pool of people may be large enough to ultimately harbor mutant strains to endanger the rest of us via pandemic reoccurance at intervals, each time a mutant strain.

We wait. We see.