In 2018 Dr Hannah Fry, lecturer on the mathematics of cities at University College London, presented Contagion: the BBC4 Pandemic in which she widely foretold Covid-19. The programme was repeated on 14 March this year. She predicted that a pandemic would start in South East Asia, be an entirely new virus, mutate from an animal source and have a devastating worldwide effect. Other contributors to the programme included mathematicians, epidemiologists and virologists. Central to their approach was an understanding of communication and social networks and their impact on the likely spread of the disease.
On 10 April, Dr Fry updated her thinking in a podcast for the Numberphile youtube Channel in the light of new knowledge about Covid-19 as the virus has spread across the world and taken hold. She compares Covid-19 to SARS (severe, acute respiratory syndrome), MERS (Middle East respiratory syndrome) and Ebola, noting that these other viruses were extremely deadly and highly visible making contact and tracing fairly straightforward. Covid-19 is not so deadly but nor is it simply ‘seasonal flu’ with a comparatively high infection but low death rate. The ‘in between’ nature of this flu, adds to its complexity.
In the podcast Dr Fry suggests that it is possible that most of the population will get Covid-19 at some point, possibly over the course of a few years until it finally does become one of the many winter flu viruses. Her thinking is based on the difficulties countries have had, for example Singapore, in closing down the virus, in contrast to the success experienced with SARS and MERS. This difficulty is because of the high number of asymptomatic and/or untested spreaders, the limited potential for a vaccine to be developed quickly and the efficacy of testing options, which currently have a high false-negative count. She stresses that ‘herd immunity’ is a likely consequence of these difficulties but is not a helpful objective. Dr Fry also considers the impact of lockdown especially for those already in poor health. As an example, she points to the high rate of maternal and infant deaths associated with, but not caused by, Ebola due to the limited availability of health services.
Dr Fry believes maths has a major contribution to make to the prevention and management of disease, but notes that if the mathematical modelling drives action helpfully then it will be assumed the disease was less serious or was not really a pandemic. And if the number of deaths (886,877 estimated for the UK in the 2018 programme) are as predicted, then the models will be deemed to have failed in helping to prevent such a high death rate.
The mathematical Covid-19 Catch 22.
