doctor wearing an anti virus protection mask to prevent others from corona covid-19 and sars cov 2 infection

2019 50s adult aid care corona coronavirus coughing cov2 covid covid19 disease doctor epidemic exhausted fever ffp2 ffp3 flu fluid health hospital hygiene incubation laboratory man mask mature old outbreak portrait protection quarantine risk sars sarscov2 sepsis symptoms test tired transmission virology virus worker workers