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

2019 50s adult aid anti care china corona coronavirus coughing cov cov2 covid covid19 disease doctor droplets epidemic fever ffp2 ffp3 flu fluid health hospital hygiene incubation infection laboratory man mask mature old others outbreak prevent protection quarantine respiratory risk sars sarscov2 sepsis sneezing symbol symptoms test transmission virology virus wearing worker wuhan