Table 1.

Impact of vaccines in the twentieth and twenty-first centuries. Data source: http://www.cdc.gov/vaccines/pubs/pinkbook/downloads/appendices/G/impact-of-vaccines.pdf.

disease	% decrease in annual morbidity	disease	% decrease in annual morbidity
smallpoxa	100	Haemophilus influenzaea (<5 years of age)	99
diphtheriaa	100	hepatitis Ab	91
pertussisa	89	hepatitis Bb (acute)	83
tetanusa	99	pneumococcusb (invasive)
polioa (paralytic)	100	all ages	30
measlesa	>99	<5 years of age	74
mumpsa	98	rotavirusb (hospitalizations <5 years of age)	88
rubellaa	>99	varicellab	89
CRSa	100

^aBased on a comparison of twentieth century annual morbidity and current morbidity.

^bBased on a comparison of pre-vaccine era estimated annual morbidity and current morbidity.