The number of infected people, measured over 70-some years and across all 50 states and the District of Columbia, generally declined after vaccines were introduced.
The heat maps below show number of cases per 100,000 people.
The number of infected people, measured over 70-some years and across all 50 states and the District of Columbia, generally declined after vaccines were introduced.
The heat maps below show number of cases per 100,000 people.