> I don’t have COVID-19 You can't know this with certainty at any given time unless you've been rigorous in avoiding social contact and other exposure, and at

> I don’t have COVID-19 You can't know this with certainty at any given time unless you've been rigorous in avoiding social contact and other exposure, and at worst the mask accomplishes nothing but does no harm (in the vast majority of cases), so there's no reason to _not_ wear a mask. > There’s no evidence that supports the idea of asymptotic spread "Asymptomatic transmission (i.e. when the infector has no symptoms throughout the course of the disease), is difficult to quantify. [...] Pre-symptomatic transmission (i.e. when the infector develops symptoms after transmitting the virus to another person) has been reported. Exposure of secondary cases occurred 1–3 days before the source patient developed symptoms." https://www.ecdc.europa.eu/en/covid-19/latest-evidence/transmission https://www.ecdc.europa.eu/en/covid-19/latest-evidence/trans... "The extent of truly asymptomatic infection in the community remains unknown. [...] Multiple studies have shown that people infect others before they themselves became ill, which is supported by available viral shedding data" https://www.who.int/news-room/commentaries/detail/transmission-of-sars-cov-2-implications-for-infection-prevention-precautions https://www.who.int/news-room/commentaries/detail/transmissi...