Like measles, most of the diseases that plagued the U.S. in the early 1900s were declining in number long before the vaccines were developed. This trend was due to factors such as
better sanitation, cleaner water, and better health care.
Whooping cough is a respiratory illness with symptoms that resemble those of other common illnesses, such as a cold, the flu or bronchitis. Before the vaccine it was considered a normal childhood disease.
Many of these diseases are just as contagious as the measles, yet, there is no fear of widespread plague or media hype associated with them.
Data source: Historical Statistics of the United States, Millennial Edition Online