Digital Life - Fighting super-spreading through modeling

NBI researchers look for the universal mechanisms which govern the processes of life. As the COVID-19 pandemic hit, their work was applied in the national mitigation strategy.

Just three months in early 2020 was all it took for the COVID-19 virus to invade practically all countries in the world. The pandemic gave us all a first-hand demonstration of a phenomenon which most people only knew from math class: the power of exponential growth.

Thinking abstractly about the origins of the pandemic, the replicative success of the COVID-19 virus illustrates how a phenomenon on the nano length-scale – tiny alterations to the surface structure of a certain protein in the virus – can have vast consequences on a global scale.

Such a span in length scales from nano to global scale is difficult if not impossible to handle in traditional medical research. Epidemiological studies will address the population scale, clinical studies will look at the patient scale, and a combination of lab experiments and theoretical work may elucidate what goes on at the atomic level. But none of these can provide the full picture. This is where physicists and their silicon replicas of the involved life processes come to the rescue.

Part of the national mitigation strategy

Long before COVID-19 hit, biophysicists at NBI became engaged in developing digital models of fundamental life processes – including how certain diseases may disturb these processes. Building on methods from physics, the researchers look for the universal mechanisms which govern the processes of life.

Early on, these proposed mechanisms will be discussed with clinical doctors, biologists, epidemiologists and others. Why? Well, a model will most often propose a given condition – such as an illness – to cause a certain physical response in the body. However, in the complex world of biology this is seldom a one-way street.

Often will the physical response in question trigger some kind of feedback which will influence the effect of the illness and possibly other bodily functions. This complexity can only be addressed through the involvement of domain experts, and these discussions will typically lead to modifications of the models.

So experienced is the group at NBI in this type of work, that the Danish health authorities (Statens Serum Institut) invited them to join the national COVID-19 pandemic mitigation efforts. Thus, the work at NBI around so-called super-spreaders soon became an integral part of the national COVID-19 management strategy.

Acknowledging that different individuals have different capacity for transmitting the virus introduces an additional level of complexity. A model developed at NBI takes this phenomenon into account and is thus a valuable tool for instance in a situation where either introducing or phasing out lockdowns is considered.

Ready for future pandemics

Much like other digital worlds created at NBI, some of the models developed by the life physics researchers require significant computing resources, and applications for time at supercomputers are sent on a regular basis. Still, this is not always the case: the program which calculates super-spreading risks in a Danish context can be run at an ordinary laptop with a calculation time of just a few hours.

Thanks to a combination of lockdowns, massive testing and vaccinations, Denmark has managed to cope relatively well with the COVID-19 pandemic in comparison with many other countries. However, the virus is still around and not least the emergence of new variants warrants continuous attention and further modifications to the developed models.

Furthermore, we have to recognize that COVID-19 will surely not be the last pandemic that we see. There will be a next one, and another one. Each time, fast development and adaptation of an accurate digital model will be instrumental in addressing the situation, saving lives and mitigating societal costs.