Is there a risk that re-opening schools will lead to a second wave of coronavirus? That’s what the government says it fears, floating the prospect of closing pubs, restaurants and shops to keep classrooms open come the autumn.
New modelling from Professor Neil Ferguson and his team at Imperial College London (ICL) published in the Lancet claims that without an effective test and trace system, re-opening schools could cause a second wave even larger than the first, resulting in hundreds of thousands more deaths.
Oddly lacking from the paper is any recognition of the failures of the team’s earlier modelling efforts to predict the outcome in Sweden or, more generally, of the need to refine their modelling in light of real world evidence and data. The mystery is why the output of this team with its discredited methods and failed predictions continues to carry any weight with policymakers around the world.
There is in fact little to no evidence that children spread the coronavirus very much if at all, probably due to their high levels of cross-immunity from other coronaviruses (common colds), as Kathy Gyngell explains here. Denmark and Norway, for instance, reopened their schools in April after only a few weeks of closure, and neither country saw a resurgence in infections. A joint report from Sweden (without primary school closure) and Finland (with primary school closure) concluded that there was no difference in infection rates between children in the two countries.
Outrageously, President Trump was censored by Twitter and Facebook for pointing out correctly that children are ‘almost immune’, Facebook ineptly labelling his assertion ‘harmful Covid misinformation’, demonstrating once again the dangers of biased social media companies taking on the role of arbiter of truth.
On the other hand, those who surely should be criticised for spreading harmful Covid misinformation are Professor Ferguson and his team at ICL. With their modelling once again ignoring the growing evidence of widespread pre-existing resistance to the coronavirus through cross-immunity and other factors, they continue simplistically to assume that everyone without antibodies remains equally susceptible to the virus, hence their continued predictions of massive death tolls that no country has yet seen, including those which didn’t lock down such as Sweden and Belarus.
Other epidemiology experts, however, such as Professor Sunetra Gupta and Professor Gabriela Gomes, have been publishing models that take into account the observed varying degrees of susceptibility and connectivity in populations, suggesting that populations can reach the threshold for collective immunity when just 10-20 per cent of the population has developed antibodies. Some models have suggested even lower thresholds.
Such models make much better sense of real world data than Ferguson’s doomsday predictions, such as why Sweden’s epidemic has all but disappeared when a survey showed 7.3 per cent antibody rate in Stockholm in late April, when the epidemic was well into decline. Also why the epidemic appeared to peak and go into decline in London, New York and Madrid before lockdown began, and in New Delhi and Mumbai after lockdown was lifted.
One of the most compelling pieces of evidence that these declines are a result of reaching a herd immunity threshold rather than any government intervention can be seen in the graph below, where the antibody rate from surveys in six cities when the epidemic was in decline is plotted against the population density.
The clear correlation here is strong evidence that the decline of the epidemics in these places – which, as noted, happened without lockdown (Stockholm), after lockdown (Mumbai, New Delhi) or likely before lockdown (London, Madrid, NYC) – is a result of the emergence of population immunity, since the herd immunity threshold is understood to increase with the population density. Furthermore, there is no relationship between antibody rates and the severity of lockdown, with Madrid, London and New York’s strict lockdown not resulting in lower values than Stockholm’s lack of lockdown.
Antibody surveys tend to show large variations in different regions of a country, and it seems likely that lockdowns and social distancing have prevented some countries and regions from reaching their herd immunity threshold, or rather have artificially lowered the threshold for as long as the restrictions remain in place. This means these places may well see a resurgence in infections as restrictions ease until the threshold proper is reached. In England, however, where the virus had already spread widely and peaked prior to lockdown, there is no reason to think these resurgences are likely to be large or that they will overwhelm health services.
There is even less reason to think opening schools will make any real difference to the spread. As the monumental costs of lockdown and social distancing continue to mount, when will the government come to its senses and steer us out of this narrow creek of misery and poverty they have navigated us into and back into the calm open waters of normality?