Epidemiological transition

Epidemiological transition is when a country or region changes from having a lot of sickness and diseases to having fewer illnesses over time. This is usually because of improvements in healthcare, such as better access to medicine and vaccines, or better ways of cleaning people's homes and drinking water. People also often live longer and healthier lives, which also helps this transition. So, even if a lot of people get sick at first, over time, as people get access to better healthcare, fewer people get sick, and the country or region changes from having a lot of sickness to having fewer illnesses.