Elderly people, malnourished people, smokers, and people with underlying medical conditions are more susceptible to neocoronaviruses. Neocoronaviruses are highly contagious and the population is generally susceptible to infection. However, the elderly are more susceptible to infection because of their decreased resistance, weakened cardiorespiratory function, and most of them have underlying medical conditions that make them more susceptible to infection. People who are chronically malnourished are more susceptible to infection because their resistance is significantly lower than normal. Long-term smokers have poorer respiratory barrier function than healthy people and are more susceptible to infection with the new coronavirus. People with underlying diseases, such as hypertension, diabetes, and chronic obstructive pulmonary disease (COPD), are more susceptible to infection with the New Coronavirus and are more likely to develop severe infections after infection, due to the depletion of immunity caused by the disease.