New model to increase contact possibilities during coronavirus pandemic

A new model will calculate scenarios for how we can have as much contact with each other as possible without increasing the coronavirus transmission rate beyond an acceptable level.

The lockdown of Danish society is costing money and has consequences for the psychological well-being of many people. Fortunately, Denmark has slowly started reopening. However, there is much to indicate that we will still have to live with various long-term restrictions.

But how much can we increase our contact with each other without COVID-19 spreading uncontrollably, and can a model be created for calculation of the different scenarios so that we can reopen our society as much as possible and in a responsible manner? Evelien van der Hurk—Associate Professor at DTU Management—will seek to answer these questions using an advanced epidemiology model which she has received DKK 1.65 million from Independent Research Fund Denmark to develop.

“The project objective is to deliver new tools that politicians and authorities can use both to evaluate ongoing activities and to compare and propose new initiatives aimed at ensuring that we can keep as many activities going as possible in society without the virus spreading more than we have the capacity to handle,” explains Evelien.

The model is based on how close contact we can have, how often, and with how many. A distinction is made between two types of contact: close contact with family and friends and peripheral contact with colleagues, when we shop, etc. The objective is to find out how many types of contact we can have without increasing the risk of infection.

Evelien explains:

“We want to develop a model that can help calculate how we can have as much contact as possible with our loved ones and the persons who are important to us, and also drop off our children, do our shopping, and perform other day-to-day activities involving light contact with others.”

Personal contact budget
This is a brand-new theoretical model, which will be based on experience from previous epidemiological models, operation analyses, network theory, data on, for example, the state of health in the population over time, infection numbers, infection risk, and the spread of infection—including from other countries—the number of meetings with the persons who are important to us, encounters with peripheral persons, and quarantine measures.

Unlike other epidemiology models, it is based on the premise that we have close contact with a few selected friends and family members—and not on our encounters with just anybody.  And where most epidemiology models evaluate 4-5 scenarios, the new model evaluates several hundred scenarios.

“We hope to be able to create some alternatives to a total lockdown where we can remain in contact with those who matter to us, without increasing the risk of infection. Imagine that we can have a kind of personal contact budget, where we decide for ourselves which meetings and contacts we will prioritize, as long as it does not increase the risk of infection on our overall contact budget. After all, it would be much easier to live with such a situation than not being allowed to go out at all or see anyone outside your household, which is —in fact—the consequence in some countries,” elaborates Evelien.

The idea behind the model is that it’s better to meet the same person ten times than to encounter ten different persons, when it comes to the risk of spreading the virus. And if the individual persons can themselves decide which of their immediate contacts they want to see, we’ll be able to have restrictions that still permit a certain contact. Some may choose close family members and friends, and others need to meet selected colleagues.”

She points out that a personal contact budget places great demands on people to manage it responsibly, but that—on the other hand—it will be possible to keep more activities going in society and boost the mental health of the population.

First version ready at the end of summer
In addition to Evelien, Professor David Pisinger from DTU Management participates in the work, and both are working on having the first results ready as early as at the end of summer.

“The first thing we deliver are tools for evaluating the different policies. Here we assess the impact of infection risk by including the concept of different contacts instead of just the number of contact moments, which is what most current models use. This will give an idea of the increased freedom we can allow from this perspective. For example, the tools can be used to assess new ways of reopening workplaces or how teenagers can safely meet with some selected friends. The next step is then to develop the actual model to evaluate and search among a large number of political objectives, and to arrive at the personal budget permissible per person,” concludes Evelien.

18 months have been allocated for development of the full model—and while the work is in progress—the researchers will continuously share their knowledge with other international universities working on similar models, including in the Netherlands and the United States.