Assessing the potential impact of transmission during prolonged viral shedding on the effect of lockdown relaxation on COVID-19.

Tepekule, Burcu; Hauser, Anthony; Kachalov, Viacheslav N; Andresen, Sara; Scheier, Thomas; Schreiber, Peter W; Günthard, Huldrych F; Kouyos, Roger D (2021). Assessing the potential impact of transmission during prolonged viral shedding on the effect of lockdown relaxation on COVID-19. PLoS computational biology, 17(1), e1008609. Public Library of Science 10.1371/journal.pcbi.1008609

Tepekule_PLoSComputBiol_2021.pdf - Published Version
Available under License Creative Commons: Attribution (CC-BY).

Download (2MB) | Preview

A key parameter in epidemiological modeling which characterizes the spread of an infectious disease is the generation time, or more generally the distribution of infectiousness as a function of time since infection. There is increasing evidence supporting a prolonged viral shedding window for COVID-19, but the transmissibility in this phase is unclear. Based on this, we develop a generalized Susceptible-Exposed-Infected-Resistant (SEIR) model including an additional compartment of chronically infected individuals who can stay infectious for a longer duration than the reported generation time, but with infectivity reduced to varying degrees. Using the incidence and fatality data from different countries, we first show that such an assumption also yields a plausible model in explaining the data observed prior to the easing of the lockdown measures (relaxation). We then test the predictive power of this model for different durations and levels of prolonged infectiousness using the incidence data after the introduction of relaxation in Switzerland, and compare it with a model without the chronically infected population to represent the models conventionally used. We show that in case of a gradual easing on the lockdown measures, the predictions of the model including the chronically infected population vary considerably from those obtained under a model in which prolonged infectiousness is not taken into account. Although the existence of a chronically infected population still remains largely hypothetical, we believe that our results provide tentative evidence to consider a chronically infected population as an alternative modeling approach to better interpret the transmission dynamics of COVID-19.

Item Type:

Journal Article (Original Article)


04 Faculty of Medicine > Pre-clinic Human Medicine > Institute of Social and Preventive Medicine (ISPM)

UniBE Contributor:

Hauser, Anthony Willy


600 Technology > 610 Medicine & health
300 Social sciences, sociology & anthropology > 360 Social problems & social services




Public Library of Science


[4] Swiss National Science Foundation




Doris Kopp Heim

Date Deposited:

04 Feb 2021 20:19

Last Modified:

13 Mar 2021 20:37

Publisher DOI:


PubMed ID:





Actions (login required)

Edit item Edit item
Provide Feedback