The Open Vaccine Journal, 2010, 3, 19-24 19 1875-0354/10 2010 Bentham Open Open Access Improving Health through Elimination and Eradication of Vaccine Preventable Diseases Àngela Domínguez 1,2, * , Eva Borràs 2,3 , Núria Torner 2,3 and Núria Soldevila 2,4 1 Department of Public Health. University of Barcelona, Spain 2 CIBER Epidemiología y Salud Pública (CIBERESP), Spain 3 Department of Health. Generalitat of Catalonia, Spain 4 Technical University of Catalonia, Spain Abstract: The last two centuries have seen an extraordinary reduction in the morbidity and mortality due to infectious diseases as a result of improvements in health and hygiene-related conditions and the introduction of vaccinations. Vaccines against infectious diseases with a human reservoir can have the following beneficial effects : control, elimination, eradica- tion and extinction of the disease. Vaccines have facilitated the eradication of smallpox in 1980 and a massive reduction in cases of poliomyelitis, of which only 1,655 were recorded worldwide in 2008. The elimination of poliomyelitis in the European region was certified by the WHO in 2002. The essential conditions for the elimination of communicable diseases are political commitment, the implementation of vaccination programmes and exhaustive disease surveillance. Keywords: Communicable diseases, elimination diseases, eradication diseases, infectious diseases, measles, poliomyelitis, smallpox, vaccination programmes. INTRODUCTION One of the most important public health achievements in the last two centuries has been the extraordinary reduction in morbidity and mortality due to infectious diseases. In most countries, this reduction began during the first half of the 19th century as a result of the increased supply and availability of food and improvements in the standard of life, and was continued in the first half of the century thanks to the adoption of environmental health measures by gov- ernments and to improvements in hygiene in general [1]. In the 20th century, vaccination played a fundamental role in reducing the impact of infectious diseases. CONTROL, ELIMINATION AND ERADICATION OF VACCINE-PREVENTABLE DISEASES Vaccines against infectious diseases with a human reser- voir can have the following benefits: control, elimination, eradication and extinction of the disease [2, 3]. Control of a disease is defined as a locally-acceptable reduction in the incidence, prevalence, morbidity and mortal- ity of a specific communicable disease as a result of specific policies. Sustaining the reduction achieved requires contin- ued vaccination programmes. Elimination of a disease is defined as a reduction to zero of the incidence of a specific infectious disease, understood *Address correspondence to this author at the Department of Public Health. University of Barcelona, Spain, 2 CIBER (CIBERESP), Epidemiología y Salud Pública Spain; Tel: 34934024566; Fax: 349304039084; E-mail: angela.dominguez@ub.edu as an infection accompanied by clinical manifestations [4] in a specific geographic region as a result of specific policies. Sustaining elimination likewise requires continued vaccina- tion programmes. Elimination is reversible, since the causal agent continues circulating outside the region in which it is eliminated and may therefore be reintroduced at any time by imported cases or small outbreaks. Therefore, surveillance is necessary to determine whether elimination is sustained in a specific re- gion or whether new cases are occurring. De Serres et al. defined elimination as a situation in which: a) endemic transmission has ceased; b) there is no sustained transmission; and c) secondary transmission from imported cases is interrupted naturally without health inter- ventions [5]. In March 2000, an expert panel on measles and public health of the Centers for Disease Control and Prevention stated that endemic transmission of a disease should be con- sidered as the existence of a chain of transmission that per- sisted for a year or more in a region in which elimination had been achieved [6]. Eradication is defined as a permanent reduction to zero in the worldwide incidence of a disease caused by a specific infectious agent as a result of specific health policies. When eradication is achieved, unlike elimination and control, vaccination programmes are no longer necessary, as there is no risk. Eradication of a disease requires a set of requirements: a) a defined and accessible reservoir of the infectious agent; b)