Naked Science Forum

Life Sciences => Physiology & Medicine => COVID-19 => Topic started by: EvaH on 08/03/2021 15:12:59

Title: What's the efficacy of the AZ vaccine on the South African variant?
Post by: EvaH on 08/03/2021 15:12:59

David asks:

Can you tell me the latest research on the efficacy of the AstraZeneca vaccine on the South African COVID variant?
I have two particular concerns; firstly that those of us who have had the AstraZeneca jab have very little protection against the South African variant, is this right? Secondly, if so, when the summer comes and restrictions are largely lifted could we have a sudden surge in cases as much of the population will mistakenly believe they are protected?

Can you help?

Title: Re: What's the efficacy of the AZ vaccine on the South African variant?
Post by: set fair on 11/03/2021 02:11:26

The j & J vacccine works reasonably well

Quote

   Please use the sharing tools found via the share button at the top or side of articles. Copying articles to share with others is a breach of FT.com T&Cs and Copyright Policy. Email licensing@ft.com to buy additional rights. Subscribers may share up to 10 or 20 articles per month using the gift article service. More information can be found at https://www.ft.com/tour.
   https://www.ft.com/content/abea44bf-e6cb-415f-8aee-1487803e154c

   Scientists at the US regulator found in a report on Wednesday that the J&J jab was 82 per cent effective at preventing severe or critical disease at its trial site in South Africa, where the 501.V2 variant was prevalent. This compares with 86 per cent efficacy in participants in the US and 88 per cent in Brazil, from 28 days after vaccination.

The vaccine was less effective at preventing moderate to severe illness in the South African group, at 64 per cent, compared with 72 and 78 per cent at the sites in the US and in Brazil.

https://www.ft.com/content/abea44bf-e6cb-415f-8aee-1487803e154c

Title: Re: What's the efficacy of the AZ vaccine on the South African variant?
Post by: evan_au on 11/03/2021 11:03:08

Quote from: David

those of us who have had the AstraZeneca jab have very little protection against the South African variant, is this right?

I think it is more accurate to say that "those of us who have had the AstraZeneca jab have much greater protection against the South African variant than those who haven't been vaccinated at all".
- And "those of us who have had the AstraZeneca jab are less likely to pass on the South African variant to our friends and family" (all other things being equal)

The South African variant still has a family resemblance to the earlier strains of COVID-19.
- Each person will generate a unique cocktail of antibodies against various parts of the spike protein (and parts of the viral coat, if they had a real SARS-COV2 infection, or are exposed to a whole-virus vaccine).
- Some of these antibodies won't recognise the South African variant
- But many of these antibodies will recognise the South African variant, and will start bringing it under control as soon as it starts an infection.
- So people who have had the AZ vaccine will be much better off than those who haven't been vaccinated

It is inevitable that follow-up "multi-valent" vaccines will be required that can provide a good immune response to multiple variants. Many vaccine vendors are already working on this.

But until multi-valent vaccines become available:
- do line up for whatever vaccine you can get (and both doses, where that is the tested configuration).
- And keep on with the usual public health measures: masks, social distancing, testing, quarantine and lockdowns (where required)