Week 32: What is known about immunity passports?

Early developments in theorising about the pandemic 

The topic of whether immunity to SARS  Cov 2 can indicate resistance to Covid-19 has been under active discussion since the beginning of the pandemic. There are 6 viruses in the coronavirus group, the first four being associated with common disorders that come and go each year, the common cold as well as influenza like illnesses. The other two are responsible for Middle Eastern Respiratory syndrome and Sudden Acute Respiratory Syndrome (SARS-Cov2).. It is this last virus that is thought to be responsible for Covid-19. The WHO produced its first paper about covid-19 on 24th April 2020, ‘Immunity passports in the context of Covid-19’. This describes a non-specific innate response to any new infection, followed by a more specific response mediated by immunoglobulins and T cells, leading to cellular immunity. 

 

The furore that followed

Publications expressing great uncertainty about using immunity to SARS-Cov2 to detect people that are resistant to Covid-19 by finding out about their immune status to the SARS virus soon followed. Kupfer N, Baylis F., Nature 2020, 581, 179-81 and Phelan AL Lancet 2020, 395, 1595 – 8are examples. The idea of immunity passports was described as the height of folly, to be fought tooth and nail. These papers are making the serious point that there are many severe inequalities in our society, and immunity passports can only make them worse. The Nuffield Bioethics committeeweighed in with a paper that recorded the uncertainties surrounding immunity to SARS-Cov2, and 

warned against ‘creating coercive and stigmatising work environments’, and argued that these are more likely to compound rather than redress work environments. 

The WHO revises its advice, but not its conclusion

The WHO have issued a revised paper ("Immunity passports" in the context of COVID-19

WHO document Update 34  02 August 2020) with greatly improved slides. (Those interested may access these slides, see attached). At the time of this revision there were 17 million cases, and over 680,000 deaths. Their revised data allows them to answer a question like ‘what % of a population has been infected with SARS-Cov2’, but cannot say what % of the group has been immune to Covid-19, and can’t be reinfected. 

 

The new slides give detailed information about other things such as memory cells, and detailed information about T cells, both CD8+ and CD4+ (helper cells). They go on to Cell destruction by CD8+ cells, and then adaptive B cells, as well as memory cells.  Someone with an eye for data display is clearly assisting them. What cannot be doubted is that immunity passports are not being recommended. Even less is known about immunity to SARS-Cov2 immunity than Covid 19 immunity. Although there is some overlap between the symptoms of SARS and those of Covid-19, they are by no means identical. Many of those who were Covid-19 positive, would not have even received the full adaptive immune process.

The slide illustrated is explaining how people who have been in contact with the Covid-19 virus may nevertheless not go through the complete immune process, and thus not produce any antibodies at all

Finally, two papers that have just appeared seem to make very different points:

 

1. Kovis V., Bennet JE, et al, Magnitude demographics and dynamics ….of the effect of Covid-19 in 21 industrialised nations. Nature Medicine 2020, published on line, 20.10.2020).

This rather difficult paper estimated all cause morbidity of the pandemic using 206,000 deaths between mid-February & May 2020. They measured deaths per 100K at risk, and overall increase in deaths. The former were similar between the sexes. England & Wales and Spain had the largest effect, accounting for about 38%, other countries had much lower effects – as little as 5% in some cases, again with no gender effects. A group of European countries including UK & Spain, but also France, the Netherlands and Scotland, started with a limited testing capacity, or ability to test in non-government labs. These countries had inadequate contact tracking systems and put lockdown measures relatively late. They can be less stringent if a sense of trust can be created with efficient testing and contact tracing systems in place. 

2. Finally, the other recent paper (Brown RC, Kelly D et al. Scientific & ethical feasibility of immunity passports. Lancet Infectious Diseases.  October 12, 2020) argues for using what is known about immunity to SARS cov2 to determine whether a proportion of our population is more protected against infection than it knows, and could therefore safely expose itself much more to external threats from Covid-19. It was this paper that caused me to write this blog! It is not an easy read, as it pursues a circuitous course through complex material. It argues that one can derive information from the SARS virus, providing various two stage precautions are taken to identify people who could safely take greater risks, and be less likely to pass the virus to another person. I found myself agreeing with their view that even if it offends by promoting inequalities, if it could be shown that a procedure works, Medicine cannot, and should not, ignore new data on efficacy.

 

Conclusion

It is dangerous to try to explain one problem (Covid-19 immunity) in terms of a different unknown (SARS Cov2 immunity). Especially difficult if we know even less about it! WHO seems unlikely to alter its views now, so we can safely stop worrying about both herd immunity and immunity passports. (I am relieved that I need no longer display my political correctness). 

(Interesting fact Completely irrelevant to this Blog: The “circuit breaker” recommended by SAGE to HMGovernment, is not as well worked out as it should be! The scientific paper to a learned journal has not been submitted, nor does there seem to be much hard data about how it is to be calculated!  DPG)

David Goldberg, still surviving, but very fortunate to be this side of the Atlantic.

28th October 2020