Clear thinking and confusion on COVID immunity

by George J. Dance

A neighborhood in Queen's, New York – ironically named Corona – may have become the first place in North America to achieve herd immunity to the coronavirua. Serological testing in New York during the summer found that 68% of the population had antibodies to the disease. If the virus spreads at an initial reproduction number (Ro) of 3 (the most common estimate), it would require 66.67% of a population to have it in order to achieve herd immunity, the point at which community transmission stops. (At an Ro of 2.5, the herd immunity threshhold would be 60%.) 

That makes Corona a very safe place to be in terms of COVID. Not completely safe, of course, as residents can still catch the disease elsewhere and bring it in; herd immunity will not prevent them from infecting anyone, only from restarting a local epidemic. The average of those with antibodies in New York is under 25%, far too low for that. And community transmission is ongoing, with the state experiencing an average 800-1,000 new cases, and 5-10 new deaths, every day. Still, the epidemic is over in New York: the virus is still spreading, and still killing, but now as a normal disease; the spread is endemic rather than an epidemic. For now the state, as its governor likes to brag, has somehow "tamed the beast." The only question is: How?    

Some religious people might say: Because we prayed, and God heard our prayers. A believer in the Church of Lockdown would say: Because the government locked us down. Both claims are similar, but the latter purports to be a scientific claim, meaning that it must be falsifiable; believers in lockdown must do more than just state the claim, but give some evidence for it besides the two events (the lockdown, and the drop in cases months later). At minimum, they have to deal with alternate hypotheses that explain the events better. 

In April, Israeli mathematician Isaac Ben-Israel analyzed the pandemic data, and noticed that outbreaks of the epidemic followed the same pattern: peaking in six weeks, then withering away after eight. Whether a atate locked down or not made virtually no difference. Therefore, he concluded, lockdown were ineffective. However, Ben-Israel, not being an epidemiologiat or virologist, had no explanation; he could only point to the numbers.

Nobel Prize winner Michael Levitt, who reached the same conclusion from the same data, noticed that the withering coincided with what he called 'saturation of infection' – a point when ~20% of the population (a figure he took from the Diamond Princess data) was no longer susceptible. Long before that point, while epidemics were still growing, their rates of growth had begun declining, an indication that the buildup of immunity was already slowing transmission. 

Others who looked at real-world data began to find the same dramatic drop at a similar infection ratio occurring around the world, from New York to Stockholm to Manaus, Brazil, to Shenzen, China.  Scientists have different theories why. One hypothesis, based on the theories of renowned epidemiologiat Sunetra Gupta, is that that there is pre-existing cross-immunity from other coronaviruas infections - enough, hypothetically, to achieve herd immunity at a lower level. Such cross-immunity may well exist, but not at that high an extent; for in none of the above communities (except possibly Shenzen) has the virus been eliminated, as herd immunity theory predicts. What has been eliminated is the epidemic, and with it most of the danger; but, as noted people are still dying of (or with) COVID in both New York and Stockholm. 

Another theory, to which I am partial, starts from the notion that "the herd" is a false analogy. Unlike a herd, where interaction is relatively the same for all, human interaction takes many different forms, within specific, limited social networks. Some people play key roles in such networks; they are more likely to get the disease, and more likely to spread it when contagious, but also more likely to block network transmission once recovered and immune. On this theory, a much lower number (~40%) of recovered patients is needed to reach "herd immunity" (at which point the disease is eliminated), while a much lower number than that would be enough to reduce the reproduction number R to ~1 (at which point the disease still spreads, but does not grow). Even some coronaviruas modellers have taken both theories seriously enough to model their assumptions, and use them to predict the pandemic's course.  

How do true believers in lockdown address the network theory, which also explains what happened in New York (and in Manauas and Stockholm, which the lockdown theory does not explain)? They don't. Rather, they first confuse the idea with the classical one of herd immunity – and, second, accuse the person who mentioned immunity of wanting more deaths simply to achieve herd immunity quicker. That was constantly done to Anders Tegnell in Sweden,  and also to Patrick Vallance in Britain, back when Britain had a no-lockdown policy. A speaker has only to mention 'immunity,' and a lockdown zealot will start ranting about 'herd immunity' instead.           

Another example occurs in this exchange between pandemic czar Antony Fauci and libertarian GOP Congressman Rand Paul. Fauci claims the epidemic ended in in New York because "they are looking at the guidelines that we have put together in the task force"; Paul points out that there is another possible explanation ("they've developed enough community immunity that they're no longer having the pandemic, because they have enough immunity"); and Fauci tries to shoot the idea down with this strawman: "If you believe that 22% is herd immunity, I believe you're alone in that." 

Paul seems to be thinking of Gupta's theory of cross-immunity, not the network theory. Still, he was clearly talking about building up a high enough degree of immunity (he says 'enough' twice) to lower the disease to New York levels, not reaching the herd immunity threshhold needed to eliminate it. Fauci either did not understand Paul's objection, or chose to misrepresent it.  

Why do they do that? Do they believe that the only possible level of immunity is herd immunity, or are they deliberately misrepresenting? Either may be possible – all that is known is that they consider the idea of 'immunity' evil, and are more concerned with eliminating it down than even considering it. It is also clear where they got that last idea; from the Bible of the Church of Lockdown, Tomas Pueyo's online writings, where the idea of immunity is discussed (not as a scientific theory, but as outright advocacy of more death:

The idea is that all the people who are infected and then recover are now immune to the virus. This is at the core of this strategy: 'Look, I know it’s going to be hard for some time, but once we’re done and a few million people die, the rest of us will be immune to it, so this virus will stop spreading and we’ll say goodbye to the coronavirus. Better do it at once and be done with it, because our alternative is to do social distancing for up to a year and risk having this peak happen later anyways.' (Tomas Pueyo, "The Hammer and the Dance")

To the best of my knowledge, no one else has ever said the sentences that Pueyo quotes.(I have searched). No one has to, as long as Pueyo's millions of readers are convinced it is what lockdown sceptics really believe down inside. The important thing then becomes not to logically answer sceptics, but to expose their evil intent. Fortunately, there are cracks in the monolith; despite everything lockdown advocates can do to suppress it, immunity theory seems here to stay.