TY - JOUR

T1 - Lockdowns exert selection pressure on overdispersion of SARS-CoV-2 variants

AU - Nielsen, Bjarke Frost

AU - Eilersen, Andreas

AU - Simonsen, Lone

AU - Sneppen, Kim

PY - 2022/9/2

Y1 - 2022/9/2

N2 - The SARS-CoV-2 ancestral strain has caused pronounced superspreading events, reflecting a disease charac-terized by overdispersion, where about 10% of infected people cause 80% of infections. New variants of the disease have different person-to-person variability in viral load, suggesting for example that the Alpha (B.1.1.7) variant is more infectious but relatively less prone to superspreading. Meanwhile, non-pharmaceutical mitigation of the pandemic has focused on limiting social contacts (lockdowns, regulations on gatherings) and decreasing transmission risk through mask wearing and social distancing. Using a mathematical model, we show that the competitive advantage of disease variants may heavily depend on the restrictions imposed. In particular, we find that lockdowns exert an evolutionary pressure which favours variants with lower levels of overdispersion. Our results suggest that overdispersion is an evolutionarily unstable trait, with a tendency for more homogeneously spreading variants to eventually dominate.

AB - The SARS-CoV-2 ancestral strain has caused pronounced superspreading events, reflecting a disease charac-terized by overdispersion, where about 10% of infected people cause 80% of infections. New variants of the disease have different person-to-person variability in viral load, suggesting for example that the Alpha (B.1.1.7) variant is more infectious but relatively less prone to superspreading. Meanwhile, non-pharmaceutical mitigation of the pandemic has focused on limiting social contacts (lockdowns, regulations on gatherings) and decreasing transmission risk through mask wearing and social distancing. Using a mathematical model, we show that the competitive advantage of disease variants may heavily depend on the restrictions imposed. In particular, we find that lockdowns exert an evolutionary pressure which favours variants with lower levels of overdispersion. Our results suggest that overdispersion is an evolutionarily unstable trait, with a tendency for more homogeneously spreading variants to eventually dominate.

KW - Overdispersion

KW - Evolution

KW - Superspreading

KW - Non-pharmaceutical interventions

KW - TRANSMISSION

U2 - 10.1016/j.epidem.2022.100613

DO - 10.1016/j.epidem.2022.100613

M3 - Journal article

C2 - 35939969

VL - 40

JO - Epidemics

JF - Epidemics

SN - 1755-4365

M1 - 100613

ER -