Masks Do More Than Protect Others During COVID-19: Reducing the Inoculum of SARS-CoV-2 to Protect the Wearer

Monica Gandhi MD, MPH, Chris Beyrer MD, MPH & Eric Goosby MD 
Journal of General Internal Medicine (2020)


Although the benefit of population-level public facial masking to protect others during the COVID-19 pandemic has received a great deal of attention, we discuss for one of the first times the hypothesis that universal masking reduces the “inoculum” or dose of the virus for the mask-wearer, leading to more mild and asymptomatic infection manifestations. Masks, depending on type, filter out the majority of viral particles, but not all. We first discuss the near-century-old literature around the viral inoculum and severity of disease (conceptualized as the LD50 or lethal dose of the virus). We include examples of rising rates of asymptomatic infection with population-level masking, including in closed settings (e.g., cruise ships) with and without universal masking. Asymptomatic infections may be harmful for spread but could actually be beneficial if they lead to higher rates of exposure. Exposing society to SARS-CoV-2 without the unacceptable consequences of severe illness with public masking could lead to greater community-level immunity and slower spread as we await a vaccine. This theory of viral inoculum and mild or asymptomatic disease with SARS-CoV-2 in light of population-level masking has received little attention so this is one of the first perspectives to discuss the evidence supporting this theory.


CCS 2020 Warm-Up

Coinciding with the Conference on Complex Systems, and profiting from the opportunity offered by the presence of a wide variety of experts in different topics, we are organising one-day school for PhD students and early-stage researchers. The school is an informal one-day event that offers early-stage scientists the opportunity to learn about the scientific and life experience of young and senior researchers, try their skills in a data visualisation and have fun playing the specifically tailored online trivia.

This year, due to a worldwide pandemic situation, the school is going to be to be held online on December 4, 2020, before the main CCS conference. The school consists of two non-scientific lectures from young scientists, ask me anything session with a prominent senior researcher, data visualisation contest and an online pub quiz. The sessions will be divided by informal coffee breaks, where participants may chatter with their peers, as in a “normal” face-to-face meeting.