“There is currently no evidence that people who have recovered from COVID-19 and have antibodies are protected from a second infection.”
From WHO a few days ago: https://www.who.int/news-room/commentaries/detail/immunity-p...
From WHO a few days ago: https://www.who.int/news-room/commentaries/detail/immunity-p...
I considered going for a deeper debunking but held off for the initial draft. I might circle back if people feel it's valuable. Let me take a quick stab though:
When we talk about immunity we need to realize the term is used imprecisely by laypeople (btw I'm totally a layman if it's not already clear).
I think of it simplistically as two components:
(1) The presence of actively circulating antibodies in the bloodstream. This is what the (oddly controversial) serology studies are measuring. It is thought that having a significant quantity of these antibodies prevents infection - i.e., what most people envision when they talk about immunity.
(2) Even after the antibodies have faded, there are still Memory B Cells, which lay dormant up to decades, waiting for exposure to the characteristic antigen (in this case, an antigen telling them that they have encountered SARS-CoV-2), at which point they resume and rapidly scale up production of antibodies.
The thinking here is that reinfection is likely possible after a sufficient length of time - whether that's a couple months or a couple years isn't yet known - but when you do get infected, your immune system will respond sooner, more strongly, and thus you will achieve a far lower peak viral load meaning a less serious infection with reduced transmisibility.
This is a robust mechanism that we see across tons of disease, including common cold coronaviruses. In my completely uncredentialed opinion, this effect is so common and well-supported that we should essentially assume it happens until we really have proof that it doesn't. I know that might sound backwards, but it really is such an enduring mechanism.
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Here's another argument you might prefer. We know that at least hundreds of thousands of people have successfully recovered from COVID-19. Loosely, we can divide the immune system into the "non-specific" and the "adaptive" subsystems. Given that we have seen extensive recovery from this illness and that those who have recovered have detectable levels of antibodies, and furthermore that there is a case of a women who could not manufacture antibodies due to a rare auto-immune disorder who failed to recover, it stands to reason that the same mechanism that provides medium-term immunity is the mechanism responsible for recovery.
That is to say, that it's very farfetched to think that people are recovering purely from non-specific immune responses and that the detectable presence of circulating antibodies is just a red herring. But I suppose you could try arguing that if you wished.
Specifically this part:
> People who assume that they are immune to a second infection because they have received a positive test result may ignore public health advice.
So, first of all, I think the concern is on its face totally unwarranted because people likely do have immunity to reinfection for several months, but regardless the presence of the immunological memory (provided they avoid getting infected with Measles which causes immunological amnesia) means that the second infection will be really not very bad and unlikely to transmit easily.
But more importantly:
Our public health organizations (and the media) have adopted the following belief: It is worth it to either mislead the public or to outright lie in order to achieve compliance. If it's not clear from the article, I find such a position detestable, not only on ideological grounds but also because functionally it causes people to endanger their health by engaging in superstition.
This is my theory on why we've seen so many articles from previously-respectable organizations like CNN that seem to focus on the narrative that young people are dropping like flies from this. Why? Because they believe that if young people are not scared shitless for their personal health, that they will not comply with the lockdown measures.
So, the WHO is really not trying to hide their motivation here.
Now the irony is I oppose immunity passports on ideological grounds, at least when used _within_ a society. As far as being used as a literal passport, that's fine by me. If the rest of the world wants to practice containment, it's welcome to do so, but I think from an evidence-based perspective, containment seems like an incredibly dangerous proposition.
This whole thing has really shaken my understanding of people.
In Italy it's pretty evident from the communication from the government, the experts (which released a "disaster story" of possible 150,000 ICU cases in a month, a number so high that should have been at least explained) and the media (including tabloids).
Since Germany has started reopening, media here (but, according to what I read - but please correct me if need be - not the case with the major German papers) started saying that "infections are accelerating elsewhere! See? Our model of lockdown is the only one that works!"
It might be true, but it should be grounded in facts and not in misrepresentation of them.
P.S.: Since you mentioned a critique of the widely-used model for this epidemic, do you have any more links to dig further? I simply do not know enough and I want to inform myself more.
The most important point of criticism is this section: https://www.lesswrong.com/posts/QuzAwSTND6N4k7yNj/seemingly-...
I don't mean this is as a criticism, but it struck me as some dissonance as I was reading.
I've also heard that there might be criticism to other models like the Imperial College one, but so far I've never found anything with some substance.
The IMHE model, after re-estimating, _was_ too optimistic. My argument does not hinge on the IMHE model being too pessimistic; but rather simply that the IMHE model is basically useless and thus we shouldn't base policy on it.
I expect us to have well over 100,000 COVID-19 deaths - indeed probably 3x that but I admit I haven't sat down and done the age-bracket-weighted mortality napkin math. (Basically, take each age group's IFR and multiply by that age group's population in the US, after multiplying by some constant <1 which represnts the sum of herd immunity threshold plus overshoot)
So basically, I think that COVID-19 mortality is going to be way worse than the model predicts, but given the way I view the cost of lockdown, etc, I still think the approach I am proposing is superior to locking down.
Does that make sense?
Some models (not published) from our expert panel in Italy are instead, in my ignorant view, very pessimistic (they say they elaborated 90 of them). The lockdown will be "eased" (quotes, for most people it's the same as before) on May 4th and one of the predictions said we'd get 150K ICU cases (as I wrote in the parent post). This looks very hyperbolic, at least on paper, because there are many measures still in place, so it's not the same as "no social distancing, no protection, everyone free".
In this case they keep mentioning uncertainty and the argument is that otherwise the public may behave in a way they don’t want. Whatever your opinion on the arguments, that’s not science and it is also poor politics because sooner or later they’ll lose credibility and really that’s all they have.
New tests for neutralizing antibodies like proposed by some groups[1] will make sure the antibodies not only are there, but that they actually work.
Also, the WHO said shit like this: https://nypost.com/2020/03/20/who-haunted-by-old-tweet-sayin...
https://www.thelancet.com/journals/lancet/article/PIIS0140-6...
Remember the other famous WHO announcement at the beginning of this outbreak: “No evidence of human-to-human transmission”