The main messages and also required knowledge from this lesson are: 

1. basic epidemiological characteristics of air-borne infections generally - type of pathogens, sources, routes of transmission, susceptible persons, occurrence,
2. main epidemiological characteristic of infuenza (types of causative agens and their infectivity for humans, sources, routes of transmission, susceptible persons, risk population, risk for healthcare workers, occurrence, prevention including vaccination),
3. main epidemiological characteristics of pertussis, pneumococcal infections, and tuberculosis - pathogens and its infectivity, sources, routes of transmission, susceptible persons, risk population, risk for healthcare workers, occurrence, prevention including vaccination.