Estimates of the Current Burden of Vaccine-preventable Diseases and of the Burden Averted by Vaccination
Table 20.2 provides WHO estimates of deaths from selected vaccine-preventable diseases for 2001, taking immunization coverage rates into account. The greatest burden of disease is in Sub-Saharan Africa, which accounts for 58 percent of pertussis deaths, 41 percent of tetanus deaths, 59 percent of measles deaths, and 80 percent of yellow fever deaths. East Asia and the Pacific has the greatest burden from hepatitis B, with 62 percent of deaths worldwide. South Asia also experienced a high disease burden, particularly for tetanus and measles.
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Table 20.2 also shows the extent of mortality in the absence of immunization and the estimated number of deaths averted by vaccination. In 2001, vaccination averted up to 52 percent of yellow fever deaths, 61 percent of measles deaths, 69 percent of tetanus deaths, 78 percent of pertussis deaths, 94 percent of diphtheria deaths, and 98 percent of polio deaths that would have occurred in the absence of vaccination. These results demonstrate the significant effect that vaccination programs have had on worldwide disease burden. The figures also show that vaccination programs have been less successful in reducing the disease burden in Sub-Saharan Africa, where coverage rates are lower.
Table 20.3 reports WHO estimates of disability-adjusted life years (DALYs) lost from vaccine-preventable diseases by region for 2001, demonstrating the high burden of disease worldwide from disability associated with sequelae of hepatitis B (liver cancer and cirrhosis), pertussis, and tetanus.2
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