500
In the 1920s there were 100,000 to 200,000 reported cases of Diphtheria each year. Now there is only approximately one case per year in the United States. Today there are around 50-100 tetanus infections in the United States per year, largely in unimmunized individuals. In 1921 there were 206,000 cases of tetanus along with 15,520 deaths reported. In the United States, between 2000 and 2008 there were 181 deaths from Pertussis, 166 of which were in infants younger than 6 months old. Prior to vaccination, in the US there were 150,000 to 260,000 cases of Pertussis reported yearly with approximately 9,000 pertussis related deaths yearly.
What is how the latest number of reported cases compares with the number before the vaccine was available?