Conditions for a Second Wave of COVID-19 Due to Interactions Between Disease Dynamics and Social Processes

• Published in: Frontiers in physics Vol. 8
• Main Authors: Pedro, Sansao A., Ndjomatchoua, Frank T., Jentsch, Peter, Tchuenche, Jean M., Anand, Madhur, Bauch, Chris T.
• Format: Journal Article
• Language: English
• Published: Frontiers Media S.A 09.10.2020
• Subjects: behavioral fatigue; coupled behavior-disease system; COVID-19; epidemic model; evolutionary game theory; SARS-CoV-2
• ISSN: 2296-424X; 2296-424X
• DOI: 10.3389/fphy.2020.574514

In May 2020, many jurisdictions around the world began lifting physical distancing restrictions against the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This gave rise to concerns about a possible second wave of coronavirus disease 2019 (COVID-19). These restrictions were imposed in response to the presence of COVID-19 in populations, usually with the broad support of affected populations. However, the lifting of restrictions is also a population response to the accumulating socio-economic impacts of restrictions, and lifting of restrictions is expected to increase the number of COVID-19 cases, in turn. This suggests that the COVID-19 pandemic exemplifies a coupled behavior-disease system where disease dynamics and social dynamics are locked in a mutual feedback loop. Here we develop a minimal mathematical model of the interaction between social support for school and workplace closure and the transmission dynamics of SARS-CoV-2. We find that a second wave of COVID-19 occurs across a broad range of plausible model input parameters governing epidemiological and social conditions, on account of instabilities generated by behavior-disease interactions. The second wave tends to have a higher peak than the first wave when the efficacy of restrictions is greater than 40% and when the basic reproduction number R0 is less than 2.4. Surprisingly, we also found that a lower R0 value makes a second wave more likely, on account of behavioral feedback (although a lower R0 does not necessarily cause more infections, in total). We conclude that second waves of COVID-19 can be interpreted as the outcome of non-linear interactions between disease dynamics and social behavior. We also suggest that further development of mathematical models exploring behavior-disease interactions could help us better understand how social and epidemiological conditions together determine how pandemics unfold.