Primary prevention is important to control the spread of the corona infection . As it is contagious one. For this Quarantine, Social distancing and use of mask is necessary along with the hand hygiene by using soap and water and 90% Alcohol based sanitizer
You are very correct with the comprehensive primary prevention measures.
However, I observed that people touch their faces often - sometimes unconsciously. So, there is tendency to touch face with contaminated hands if we are not consciously avoiding the act of face touch!
Wearing a mask or facial covering is very important in prevention the spread of Covid-19. There are two important moments. First, it keeps people from touching their face. Secondly, if someone is coughing or sneezing, it provides a guard against spreading droplets to other individuals. Social distance and hand hygiene are also important.