number of cases of most vaccine-preventable diseases is at an all-time low

Nov 14 2007

A comparison of illness and death rates for 13 vaccine-preventable diseases in the U.S., before and after use of the vaccine, indicates there have been significant decreases in the number of cases, hospitalizations and deaths for each of the diseases examined, according to a study in the November 14 issue of JAMA: The Journal of the American Medical Association.

In the United States, vaccination programs have made a major contribution to the elimination of many vaccine-preventable diseases and significantly reduced the incidence of others. “Vaccine-preventable diseases have societal and economic costs in addition to the morbidity and premature deaths resulting from these diseases—the costs include missed time from school and work, physician office visits, and hospitalizations,” the authors write. National recommendations provide guidance for use of vaccines to prevent or eliminate 17 vaccine-preventable diseases.

Sandra W. Roush, M.T., M.P.H., of the Centers for Disease Control and Prevention, Atlanta, and colleagues with the Vaccine-Preventable Disease Table Working Group, examined the illness and death rates before and after widespread implementation of national vaccine recommendations (in place before 2005) for 13 vaccine-preventable diseases. The diseases were diphtheria, pertussis, tetanus, poliomyelitis, measles, mumps, rubella (including congenital rubella syndrome), invasive Haemophilus influenzae type b (Hib), acute hepatitis B, hepatitis A, varicella (chickenpox), Streptococcus pneumoniae and smallpox.

For eight diseases for which a vaccine was licensed or recommended prior to 1980, the comparison of the period before national vaccination recommendations vs. the 2006 number of reported cases shows greater than 99 percent declines in the number of cases for diphtheria (100 percent), measles (99.9 percent), paralytic poliomyelitis (100 percent), rubella (99.9 percent), congenital rubella syndrome (99.3 percent), and smallpox (100 percent). Smallpox has been eradicated worldwide, and endemic transmission of poliovirus, measles virus, and rubella virus has been eliminated in the United States. There were no reported deaths due to diphtheria, measles, mumps, paralytic poliomyelitis, or rubella; deaths due to congenital rubella syndrome are not reported. The decline in cases of mumps was 95.9 percent, of tetanus 92.9 percent, and of pertussis 92.2 percent. The decline in tetanus deaths was 99.2 percent and in pertussis deaths 99.3 percent.

For five diseases for which a vaccine was licensed or recommended after 1980 but before 2005, cases of invasive Hib disease declined 99.8 percent or greater and deaths declined 99.5 percent or greater; for hepatitis A, reduction in cases was 87.0 percent, deaths 86.9 percent; a decrease of 80.1 percent in cases and 80.2 percent in deaths for acute hepatitis B; a decline of 34.1 percent in cases and 25.4 percent in deaths for invasive pneumococcal disease; and a reduction of 85.0 percent in cases and 81.9 percent in deaths for varicella. Hospitalizations declined by 87.0 percent for hepatitis A, 80.1 percent for acute hepatitis B, and 88.0 percent for varicella.

“The number of cases of most vaccine-preventable diseases is at an all-time low; hospitalizations and deaths from vaccine-preventable diseases have also shown striking decreases. These achievements are largely due to reaching and maintaining high vaccine coverage levels from infancy throughout childhood by successful implementation of the infant and childhood immunization program,” the authors write.

“Vaccines are one of the greatest achievements of biomedical science and public health. Continued efforts to improve the efficacy and safety of vaccines and vaccine coverage among all age groups will provide overall public health benefit. The challenges in vaccine development, vaccine financing, surveillance, assessment, and vaccine delivery are opportunities for the future,” the authors conclude.

http://jama.ama-assn.org/