Weren't we trying to achieve herd immunity? We heard a lot about it in the early stages; not so much now. Wasn't the idea to achieve it via a combination of antibodies from prior infections and vaccines? Not just vaccines? So, why has discussion of natural herd immunity been completely sidelined?
It seems as though the idea was stillborn, because of a concern that the cost of achieving it was too high. That too many people would have to die and that unproven lockdowns were a better option. The precautionary principle writ large; an abundance of caution.
But given the fact that Covid doesn't seem to have paid much attention to our best efforts and has allegedly spread widely anyway, is herd immunity going to be achieved despite us? And what part could natural, pre existing immunity play?
A little bit of science; B cells produce antibodies, but are regulated by T cells. T cells react to viruses on infected cells, while B cells help prevent them being infected in the first place. Hence, what we understand to be traditional vaccines and an actual viral infection both produce B cell antibodies, whereas mRNA 'vaccines' target the T cells and only fight the infection once it has taken hold.
Public health responses, worldwide, have been based on the assumption that there was no pre-existing immunity. That's why you've heard it referred to as a novel coronavirus and that's why serological testing has been done – which would detect B cell immunity – but T cell testing has been neglected. If you're proceeding on the basis that the virus is new, why would you need to check for existing T cell immunity? One might, of course, question the competence or motivation of a scientific establishment that went all in on that hypothesis without testing it adequately, which is a process that scientists learn in high school.
In any event, at least six studies have reported T cell reactivity against Covid in 20-50% of people with no known exposure to the virus. And before you say that these were likely asymptomatic people who hadn't realized that they'd had the virus, one study used blood samples from 2015-2018. It's believed that this response is due, at least in part, to common cold coronaviruses, which are closely related.
It turns out that this is not a new phenomenon – the 2009 Swine Flu outbreak was very similar. That died out much sooner than expected, as pre-existing immunity effectively deprived the disease of the conditions it needed to thrive. With regard to that 'pandemic', the CDC even said that
'the vulnerability of a population to a pandemic virus is related in part to the level of pre-existing immunity to the virus',(1)
an observation of epic vacuity.
You'd think that this discovery, coupled with the knowledge that those that recovered from Covid would also have immunity, might have been something that would have been widely shared. A source of hope, perhaps. But I'll wager that you know little or nothing about it. Why is that?
Most experts (and we now have to use that phrase carefully, given the politicization of science) have concluded that at least 50% of a population need to be infected with the actual virus to achieve herd immunity, a strikingly low number when compared to government propaganda. Others have pointed out that, depending on the proportion of pre-existing immunity, 10-20% is a more accurate estimate and that the difference is made up of people who have achieved immunity by exposure to a similar disease in the past.(2)(3)
Covid 19 is very infectious. However, even in areas that have been hard hit, such as London and New York, serological testing reveals that antibodies exist in only 18% and 23% of people, respectively. If the data are saying that immunity is at that level, then when a lockdown is eased, infection rates should take off again. After all, there is a large, uninfected target constituency to aim for. I'm guessing that you think that is exactly what happens, because that's the impression you've been given. It doesn't.(4)
Explanations such as a strict adherence to social distancing are possible, but scientists do not deem any such preventative measures to be the likely reason. This will strike a chord with most of us, who know that social distancing, in particular, has been honored more in the breach than in the observance.
Rather, it seems to be because protective levels of immunity, not measurable through serology alone, but instead the result of a combination of pre-existing and newly formed immune responses on our T cells, could now exist in the population, preventing an epidemic rise in new infections.(5) And given Covid's infectivity, that proportion is likely to be a significant one.
Another large study in Sweden, which investigated close family members of patients with confirmed Covid, found that 60% had antibodies (B cell immunity) and 90% had T cell active responses.(6)(7) If we do the math, that indicates that 20-30% had been infected and did not produce antibodies and 50-60% had both types of response.
Whilst there are conflicting opinions as to the length of time that B cell immunity affords an individual, it has been proven that T cells that react to SARS-COV-1 are still present in patients 17 years after infection.(8) If T cells with Covid immunity behave in a similar way, which seems likely, it would seem to be more encouraging news, but once again, I'm betting that most of you have no knowledge.
In any event, it can be seen that serological testing for antibodies is not the whole game. T cell immunity also needs to be tested in order to understand the full picture. It would also seem sensible to establish whether pre-existing immunity is more protective than vaccinations. It probably won't surprise you to learn that there are no such studies ongoing on either front.
It might pay us to look again at the reasons given to us to justify what, by any measure, has been a considerable diminution of our societal rights. One of the central tenets has been that this is a new, highly contagious disease to which we have no natural defense. It would seem that this contention is false. Not only that, it is clear that it was known that it was likely to be false when it was stated, given the previous experience with Swine Flu and yet there was no official equivocation and there is still no official scientific curiosity, no ongoing studies testing the hypothesis.
Why have we put all our eggs in the vaccine basket? Why aren't people being tested serologically so that those with antibodies can make an informed choice about whether to have a vaccination? And, especially, why are we not conducting T cell immunity studies? I wish I could tell you more, but the information is not available; the studies have not been done and are not in prospect, either. In a normal world, this would seem inexplicable. We should not still be asking these questions over a year later. But we are.
Citations
Considerations for assessing the severity of an influenza pandemic. Wkly Epidemiol Rec 2009;84(22):197-202.
Aguas R, Corder RM, King JG, Goncalves G, Ferreira MU, Gomes MGM. Herd immunity thresholds for SARS-CoV-2 estimated from unfolding epidemics [preprint]. MedRxiv. 2020. https://doi.org/10.1101/2020.07.23.20160762.
Gomes MGM, Corder RM, King JG, Langwig KE, Souto-Maior C, Carneiro J, et al. Individual variation in susceptibility or exposure to SARS-CoV-2 lowers the herd immunity threshold [preprint]. MedRxiv. May2020. https://www.medrxiv.org/content/10.1101/2020.04.27.20081893v3.
BMJ 2020;370:m3563 http://dx.doi.org/10.1136/bmj.m3563, Sunetra Gupta
Ditto
BMJ 2020;370:m3563http://dx.doi.org/10.1136/bmj.m3563
Sekine T, Perez-Potti A, Rivera-Ballesteros O, et al. Robust T cell immunity in convalescent individuals with asymptomatic or mild COVID-19 [preprint]. 2020 https://www.biorxiv.org/content/10.1101/2020.06.29.174888v1.abstract.
Le Bert N, Tan AT, Kunasegaran K, etal. SARS-CoV-2-specific T cell immunity in cases of COVID-19 and SARS, and uninfected controls. Nature 2020;584:457-62. .doi: 10.1038/s41586-020-2550-z pmid: 32668444