The aim of current paper is to analyze air quality monitoring possibilities in public transport vehicles. Using IoT, to offer the prototype for air quality monitoring in public transport vehicles and provide recommendations to ensure its sustainability also in unsafe epidemiological situation. The practical value of the work is the developed Internet of Things prototype, which is equipped with CO2, temperature and humidity sensors. The measurement results are sent using the MQTT protocol, as well as the measurement results are reflected in the form of graphs. In the experimental part of the research, measurements were made in the following types of public transport - buses, trams and trolleybuses. Also, when taking measurements in public transport, the author observes differences in CO2 rise and differences in temperature fluctuations, depending on the type of public transport. It can be said that similar prototypes can be a useful solution to be able to make measurements in public transport. The developed prototype provides an opportunity to connect several Internet of Things devices, expanding its functionality, as the advantages of the MQTT protocol can be used. The framework for ensuring of adapting the public transport system to the COVID-19 challenge and other epidemiological threats, for ensuring public transport system`s sustainability is described in the form of recommendations provided for the sustainable development of the public transport system, considering unsafe epidemiological conditions. Recommendations offered for all main stakeholders.