Assessment of the effectiveness of Omicron transmission mitigation strategies for European universities using an agent-based network model

TL;DR

This study uses an agent-based model to evaluate COVID-19 mitigation strategies in European universities, revealing that current measures may be insufficient to prevent outbreaks with Omicron, even with high vaccination and mask mandates.

Contribution

It provides a data-driven simulation framework to assess the effectiveness of existing mitigation strategies in university settings during Omicron outbreaks.

Findings

High vaccination coverage alone is insufficient to prevent large outbreaks.

Reducing occupancy and mask mandates are not enough to control Omicron spread.

Controlling transmission requires additional measures beyond current strategies.

Abstract

Returning universities to full on-campus operations while the COVID-19 pandemic is ongoing has been a controversial discussion in many countries. The risk of large outbreaks in dense course settings is contrasted by the benefits of in-person teaching. Transmission risk depends on a range of parameters, such as vaccination coverage and efficacy, number of contacts and adoption of non-pharmaceutical intervention measures (NPIs). Due to the generalised academic freedom in Europe, many universities are asked to autonomously decide on and implement intervention measures and regulate on-campus operations. In the context of rapidly changing vaccination coverage and parameters of the virus, universities often lack sufficient scientific insight to base these decisions on. To address this problem, we analyse a calibrated, data-driven agent-based simulation of transmission dynamics of 10755 students and 974 faculty members in a medium-sized European university. We use a co-location network reconstructed from student enrollment data and calibrate transmission risk based on outbreak size distributions in education institutions. We focus on actionable interventions that are part of the already existing decision-making process of universities to provide guidance for concrete policy decisions. Here we show that, with the Omicron variant of the SARS-CoV-2 virus, even a reduction to 25% occupancy and universal mask mandates are not enough to prevent large outbreaks given the vaccination coverage of about 80% recently reported for students in Austria. Our results show that controlling the spread of the virus with available vaccines in combination with NPIs is not feasible in the university setting if presence of students and faculty on campus is required.