Author Topic: Antigenic Sin  (Read 937 times)

Buelligan

  • STOP being afraid
Antigenic Sin
« on: August 03, 2021, 09:37:25 AM »
I don't normally visit this board, happy enough with GB but was just watching last night's Tyskysour and saw this.  Pause the vid and read the image because Michael Walker doesn't speak about all of what is written there.  What is written there is that, in a new bit of thoughts released from SAGE, where they're pondering on how the virus may mutate they talk about issues that are highly relevant to the vaccination programme and rather concerning for those being vaccinated and all of us who want to end this terrible thing (along with giving their estimation of how likely that scenario is to become a reality).  In this section they say -

Quote from: that SAGE document
Antigenic drift:  A gradual or punctuated accumulation of antigenic variation that eventually leads to current vaccine failure.  Worst case is that this combines with significant antigenic sin (vaccination that results in an immune response that is dominated by antibodies to previously experienced viruses/vaccines) meaning that it becomes difficult to revaccinate to induce antibodies to the new strains.  Genetic and antigenic drift are almost inevitable.  Antigenic sin has not yet been reported for SARS-CoV-2, so we consider this possibility less likely.

Likelihood: Almost certain.  Impact:  Medium.

Whilst I take some encouragement from the estimated Medium impact, we're talking about a scenario that has already killed a frighteningly large number of people, so a Medium score, on that scale seems rather frightening.

So this issue of antigenic sin - could it mean that countries where very high levels of vaccination are achieved are hugely more exposed, should this happen?  I'm not a virologist or a geneticist, it's the first time I've heard of this thing but it seems like a thing people need to know about.

ETA:  Just to be clear, vaccinating people who've not had the disease and are in high risk groups, seems eminently sensible but, in the light of this, is vaccinating people who will almost certainly only experience low level symptoms but may not then be able to receive antibodies to future, far more dangerous, strains (when they're older, for instance) a wise move?  I do not know but I think it needs research and discussion.

Re: Antigenic Sin
« Reply #1 on: August 03, 2021, 12:53:05 PM »
The answer is vaccinate as many people as possible ASAP. Longer there's a big group who can't be arsed or won't, the more chance of fucksponential gravedown.

Zetetic

  • I wasn't supposed to be around this long, so…
Re: Antigenic Sin
« Reply #2 on: August 03, 2021, 12:58:38 PM »
It's hard to see how there's not going to be huge groups for months if not years - both here and worldwide.

Buelligan

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Re: Antigenic Sin
« Reply #3 on: August 03, 2021, 01:04:13 PM »
That's the problem, isn't it?  Even if you can do the whole country, like climate catastrophe, these things do not respect human borders.  How are you going to do the whole world, in or out of a capitalist system?  In a capitalist system, even harder.

Buelligan

  • STOP being afraid
Re: Antigenic Sin
« Reply #4 on: August 03, 2021, 01:13:29 PM »
Just to add, I'm unclear, for instance, if you've already had the disease (naturally) and are producing antibodies (naturally), what risk, if any, compared to the risk for vaccinated groups do you carry of finding you cannot accept future vaccination against far more virulent strains? 

I might be being idiotic but to me anyway, this information, these sorts of questions, seem highly relevant and yet no one seems to be talking about it at all.  I admit, I don't prowl round the internet or news sites looking for covid chats, so maybe it's all out there but I really feel that organisations like SAGE and governments should be keeping people informed, not just corralling them down preordained avenues, without information.

Re: Antigenic Sin
« Reply #5 on: August 03, 2021, 01:52:50 PM »
It's impossible to reach a concrete conclusion, this is risk assessment and speculation.

Keep it simple for the moment.

If you haven't been vaccinated, get vaccinated.

Plenty of countries are miles behind and there will probably be consequences but the more people vaccinated sooner the better.

Re: Antigenic Sin
« Reply #6 on: August 03, 2021, 02:01:48 PM »
This article covers the issue without too getting overly technical: https://www.statnews.com/2021/04/16/next-generation-covid-19-vaccines-are-supposed-to-be-better-some-experts-worry-they-could-be-worse/.

One sentence summary: Sars-Cov-2 evolves much more slowly than viruses where antigenic sin is a problem and the spike protein it uses has less potential for evolution too so it's less likely to be an issue than with flu vaccines, especially for those who have had mRNA vaccines.

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