As health officials in three Ontario cities are warning the public of confirmed cases of measles, doctors are pointing out how important vaccines are and how to minimize the risk of outbreaks in the future.

“There are few things in the history of health that have truly changed life for the better,” says Dr. Danielle Martin, vice president of medical affairs and health system solutions at Women’s College Hospital, to Kevin Newman Live. “One of them is separating our sewage and the other is using vaccines to prevent illnesses like measles.”

Dr. Sydney Spiesel, a pediatrician in Connecticut and professor at Yale, describes it slightly differently in a recent blog for Slate.

“If you were to take all the pediatricians and stuff them in a barrel and fling them over Niagara Falls, the world would not be so badly off,” Spiesel writes. “The same cannot be said about vaccines: Getting rid of them would be a real disaster.”

The measles outbreak in Ontario comes almost three weeks after one in New York. To read more: