This isn't Original Antigenic Sin

This is "hybrid immune damping"

An interesting paper was published yesterday, all about the immune response to Omicron in the vaccinated.

The paper is fairly long and complex, but to summarise:

• They found that in vaccinated individuals that had prior infection, the immune response to Omicron variant was to improve the immune protection to earlier variants, but offered very little protection to Omicron variant.

• And that in vaccinated individuals that had no prior infection, the immune response to Omicron variant was to improve the immune protection to earlier variants, but offered very little protection to Omicron variant.

You might think that this sounds very much like Original Antigenic Sin, or OAS — that is, the immunological phenomenon whereby the first infection of a particular type of disease primes the immune system and it responds to future infections as though it was the first infection, whether or not the immune response (optimised for that first infection) is going to work.

If you did think it sounds like OAS you’re in good company — I think it sounds exactly like OAS as well…

… However, the authors of the paper didn’t think it sounded like OAS — indeed, they didn’t mention OAS in the paper at all. Instead they invented a new term, Hybrid Immune Damping, to describe the effect. They don’t even describe hybrid immune damping as a subset of OAS, it simply isn’t mentioned at all in the paper. The only reason I can think of them taking the approach of inventing a new term for an existing phenomenon is that they don’t want to offer any suggestion that all those that predicted this outcome might have been correct...

What’s worse is that the inability of the immune system of the vaccinated-infected to build protection against future variants wasn’t limited to reduced effectiveness of neutralising antibodies. We’ve known for some time that antibodies aren’t used for immune protection against coronaviruses (in general, not just SARS-CoV-2) — instead the immune protection is largely dependent on T-cells. The authors found that the ability of T-cells to protect against Omicron type variants was also significantly impaired in vaccinated individuals. This is very concerning.

An odd aspect of the authors’ analysis of the situation was that they considered the problem to lie entirely with the immune response to the earlier variants — there’s no suggestion that the problem might lie with the vaccines. This is despite the problem also being seen in individuals whose first exposure to Covid was Omicron variant — they also had an immune response optimised to protect against earlier variants and not Omicron variant. I find it very odd that the authors didn’t discuss the possibility that it is the vaccines that have caused the hybrid immune damping; they express surprise that a slightly different type of coronavirus can have this strange effect, but not novel vaccine technologies with little in the way of long term testing.

The authors only examined the immune response in vaccinated individuals, so we don’t know whether it will be the case for naturally infected-unvaccinated individuals — however, I note that infected-unvaccinated individuals will have an immune exposure to all of the proteins of Covid, most of which change only slowly; unlike vaccinated individuals this ‘first immune exposure’ to Covid should result in at least some maintained protection against Covid, even if OAS hybrid immune damping also exists in the unvaccinated.

Whatever we call it, the outcome of this mess would appear to be that individuals will be more likely to have frequent reinfections with Covid — we were promised that we’d reach herd immunity and Covid would die out, but instead we seem to be faced with a future made up of endless Covid waves, each with non-trivial numbers of hospitalisations and deaths.

No wonder our authorities desperately want us to forget about Covid.