The editors of PLOS Medicine together with Guest Editors Prof. Zulfiqar A. Bhutta, Prof. Kathryn M. Yount, and Prof. Quique Bassat, announce…
Alexandra Teslya, Thi Mui Pham, Noor Godijk, Mirjam Kretzschmar, Martin Bootsma and Ganna Rozhnova from the University Medical Center Utrecht (The Netherlands) developed a computational model of the spread of COVID-19 and studied the effect of various prevention measures on the number and timing of COVID-19 cases.
The coronavirus disease COVID-19 has spread to nearly every country in the world and has put an unprecedented strain both on the healthcare and economic sector. By the first week of April, more than half of the world’s population was under some form of mandated lockdown that aimed to promptly slow down epidemic growth. This restrictive intervention carries a significant social and economic burden, but is highly suitable when time is needed to develop a vaccine, for healthcare systems to treat existing cases or to increase capacity. As stringent lockdowns cannot be enforced indefinitely, many countries are gradually lifting them. In the light of the current unavailability of a robust vaccine, we need to stay vigilant and consider additional measures in order to avoid potential epidemic resurgence and the need to reimpose lockdowns. Widespread adoption of simple precautionary measures may be the key to prevent second waves and relieve the pressure on healthcare systems.
Our study shows that if a population quickly becomes aware of the coronavirus, the concomitant behavior change can have a significant impact on the course of the epidemic. Personal protective measures such as handwashing, mask-wearing and self-imposed social distancing can both diminish and postpone the peak number of cases, provided their efficacies exceed a certain threshold. If individuals quickly adopt and sufficiently adhere to these measures, a large epidemic could be prevented. However, if self-imposed prevention measures are slow to catch on, they may reduce the number of cases but will not delay the epidemic peak. On the other hand, government-imposed social distancing that is implemented early in the epidemic is effective in delaying but not in reducing the peak of the outbreak. As often, no single intervention will fit all goals. However, joining several prevention strategies can be effective when aiming both at buying time and slowing epidemic spread. Moreover, the combination of measures is more effective than they are on their own.
It’s important to note that there are limitations to our study. For example, our model does not account for demographics, imperfect isolation of COVID-19 patients, or the possibility of reinfection. Moreover, for a correct interpretation of our results, realistic efficacy values of a specific measure need to be considered.
Our results highlight the importance of disease awareness in controlling the ongoing epidemic. Many self-imposed prevention measures are minimally disruptive and have limited impact on the economy. If regularly maintained, they may significantly contribute to preventing a resurgence of the virus and subsequently a second lockdown. We, therefore, recommend that government and public health institutions continuously mobilize people to adopt and maintain self-imposed measures with scientifically proven efficacy in order to successfully tackle COVID-19.