An epidemic running out of steam

As in London and New York, so now in Delhi. Results from a survey in the Indian capital released this week show 23.5 per cent antibody rate for the coronavirus.

This figure, from a survey of 21,387 citizens conducted between June 27 and July 10 by the Indian Centre for Disease Control, is similar to the 19.9 per cent antibody rate found in New York in April after the virus had receded there and the 17 per cent found in London also in April as the virus was on the way out.

The data from Delhi provides further illumination of the nature of this virus and the limited impact of lockdown in altering its course. A strict national lockdown was imposed in India on March 22 but, as in New York and London, no effect on the epidemic curve is visible from this huge intervention.

One difference between the cities is that whereas in London and New York new infections appear to have begun falling before lockdown began, in Delhi the epidemic only really seemed to get going after lockdown was imposed, with the positive test rate not peaking until mid-June. Yet despite the national lockdown being lifted at the end of May, the positivity rate in the capital peaked and went into sustained decline two weeks after the lockdown ended, suggesting an epidemic running out of steam.

Source: https://www.hindustantimes.com/india-news/delhi-may-go-past-covid-peak-in-aug-if-cases-keep-falling-experts/story-nUyp7Wt3nYIjqdUTyby3DP.html

The results from Delhi are a further confirmation of the epidemic models developed by Professor Sunetra Gupta’s team at Oxford University and Gabriela Gomes’s team, which found that herd immunity could be expected at around 20 per cent antibody rate once cross-immunity from other coronaviruses and other factors reducing susceptibility are taken into account.

In terms of the differences in the antibody rates between the cities, perhaps the answer lies not so much in government interventions and social distancing as in demographic factors such as population density. Take a look at the population densities in the three cities: London has 14,766 people per square mile, New York City around 27,000 and Delhi 29,259. These ascend in the same order as the antibody rates. Similarly, the 7.3 per cent antibody rate in Stockholm in April, as the epidemic was in decline, corresponds to a population density of around 13,000 per square mile. As a new study in the Lancet confirms, there is no relationship between lockdown interventions and death toll in different countries: ‘Rapid border closures, full lockdowns, and wide-spread testing were not associated with COVID-19 mortality per million people.’ On the other hand, ‘population characteristics’ were associated with increased overall mortality.

One curiosity is the low death rate in Delhi, given the high antibody and hence infection rate. Officially it is just 3,751 deaths as of 18 July, corresponding to a less than 0.1 per cent infection fatality rate (IFR) (assuming all infections produce antibodies). Even if this is an undercount it is a long way from the 0.863 per cent IFR calculated for New York City. Reasons for the lower IFR could include that we now have a better understanding of how to treat the virus, that India is affected by a milder strain, the younger age profile and lower obesity rate of Delhi’s population, and differences in levels of natural and cross-immunity in the populations. It may also be related to the fact that India has been a leading user of the cheap over-the-counter drug hydroxychloroquine (HCQ), as TCW has reported.

With the evidence growing by the day that the primary driver of epidemic decline in cities such as New York, London and Delhi is the early emergence of collective immunity, the mystery is why the mainstream narrative of fear will not be budged. The BBC was at it again this week, publishing a long article giving the orthodox version of the history in which ‘herd immunity’ is the big baddie which the government foolishly took seriously in February and March – until Professor Neil Ferguson turned up to show them the error of their ways – and so failed to lock down early enough to save thousands of lives.

But as Professor Gupta, who was interviewed this week for the Reaction website (we’re still waiting for her BBC interview), explained: herd immunity is ‘just a technical term for the proportion of the population that needs to be immune in order to prevent the disease from spreading, which is the central concept in vaccinations’.

‘The truth is that herd immunity is a way of preventing vulnerable people from dying,’ she said. ‘It is achieved at the expense of some people dying, and we can stop that by preventing the vulnerable class in the process. In an ideal situation, you would protect the vulnerable as best you can, let people go about their business, allow herd immunity to build up, make sure the economy doesn’t crash, make sure the arts are preserved, and make sure qualities of kindness and tolerance remain in place.’

That is what we should have done. It is also what we should now do. The government needs to start listening to scientists such as Professor Gupta, whose models are correctly predicting the results on the ground, rather than scientists such as Neil Ferguson, whose models have consistently fallen flat. Ministers need to learn the lessons that London, New York and now Delhi are teaching us about this virus: that there is no sign of lockdowns changing the course of the epidemic; that there have been no surges as restrictions have eased, and that antibody rates in hotspot cities are consistently around a fifth of the population, likely telling us something important about when collective immunity kicks in.

Heed the data, heed the models that best explain the data, and heed the scientists who devise or back them. Dispel the fear of the virus and the second wave from which we must it seems forever hide. Start leading the nation back to normality.

First published on Conservative Woman.

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