80% of people won’t contract covid-19 – Professor

Up to 80 per cent of people might not be susceptible to the COVID-19 coronavirus, according to the world-renowned neuroscientist Professor Karl Friston in an interview with UnHerd’s Lockdown TV, casting doubt on the current approach to containing the virus.

Until recently, scientists have assumed that the majority of the population is susceptible to catching COVID-19, but a lack of research and the fact that the virus often shows no symptoms has made it difficult to confirm. Based on this risk of widespread contamination, governments have put in place economically damaging lockdown measures aimed at limiting the spread of coronavirus to protect healthcare systems from being overwhelmed.

But according to Professor Friston, who was recently ranked the world’s most influential neuroscientist by Science magazine, the majority of the population likely had some sort of “prior immunity” to COVID-19 – and therefore would not have caught it in the first place.

Friston’s claims build on a growing shift toward a consensus that some people are not susceptible to coronavirus, following Michael Levitt’s argument in early May that mathematical data models did not show exponential growth in coronavirus.

Instead, Friston said that he expects ongoing research to reveal that the majority of the population in the UK, his home country, are not susceptible to the disease.

“I suspect, once this has been done, it will look like the effective non-susceptible portion of the population will be about 80 percent. I think that’s what’s going to happen,” he told UnHerd’s Freddie Sayers in an interview published on Friday.

As a neuroscientist famous for inventing the “statistical parametric mapping” brain imaging technique, Friston is not an epidemiologist or disease specialist and instead bases his claims on applying a modelling analysis to COVID-19 data.

Friston does not claim to have identified the actual antibody that could make people immune to the virus. Instead, he argues that the data suggests that a vast number of people have some sort of “immunological dark matter” – a form of resistance to infection that we have not yet identified.

As UnHerd’s Sayers noted, this does not mean that that the non-susceptible portion of the population is technically immune to the virus, but instead that they are unlikely to contract it “under normal circumstances,” without being exposed to a high viral load in a hospital, for example.

Friston’s claims have wide-reaching implications for governments as they attempt to deal with the coronavirus pandemic.

According to Friston’s model, government policy is not the main explanation for varying death rates from country to country. Instead, he argues that the percentage of the population that is susceptible to COVID-19 has the strongest influence on a country’s death rate.

“Solving that — understanding that source of variation in terms of this non-susceptibility — is going to be the key to understanding the enormous variation between countries,” Friston told UnHerd.

For example, Friston said that Germany has a far lower death rate than the UK not primarily because of testing or lockdown policies, but instead because the “susceptible population” in Germany is much smaller.

While Friston acknowledged that we need more research, the implications of his modelling are vast.

If correct, governments would be able to completely reconsider their approach to lifting lockdowns.

If it is true that 80 percent of the population cannot catch COVID-19, then social distancing measures may not need to be put in place in a post-lockdown scenario – public transport could restart, entertainment and hospitality venues could reopen, and sport could resume, all without any major risk of a second spike.

Friston added to UnHerd TV that incorporating “sensible behavior” into the model, such as people who do catch COVID-19 likely staying in bed when they are sick, then lockdown measures have a negligible impact at most.

On reflection, this would mean that governments have made vast economic sacrifices by imposing lockdowns – with the IMF predicting the worst global recession in a century – without them having any real affect on the spread of the virus. It would also mean that fears that coronavirus might destroy industries such as hospitality might be misplaced.

However, research on the coronavirus remains ongoing, and the scientific community continues to disagree over almost all of the key questions.