Skip Navigation LinksSkip Navigation Links
Centers for Disease Control and Prevention
Safer Healthier People
Blue White
Blue White
bottom curve
CDC Home Search Health Topics A-Z spacer spacer
Blue curve MMWR spacer

Persons using assistive technology might not be able to fully access information in this file. For assistance, please send e-mail to: Type 508 Accommodation and the title of the report in the subject line of e-mail.

Notice to Readers: 25th Anniversary of the Last Case of Naturally Acquired Smallpox

On October 26, 1977, the last case of naturally acquired smallpox occurred in the Merca District of Somalia. In May 1980, the World Health Assembly certified the world free of naturally occurring smallpox. The eradication of a disease was an unprecedented accomplishment. Eradication efforts for both paralytic poliomyelitis and dracunculiasis (i.e., guinea worm disease) are ongoing. Beyond the benefit to the world population's health and economy, smallpox eradication demonstrated the benefits of international commitment and cooperation toward a common cause in public health. Improvements made in international vaccination programs, global disease surveillance, and public health logistics systems that were results of the smallpox eradication program continue today (1).

Although smallpox was eradicated in 1977, the risk for importation of disease into the United States had greatly decreased before that time. As a result, the United States discontinued routine smallpox vaccinations for the general population in 1971, and the Advisory Committee on Immunization Practices recommended against routine vaccination of health-care workers in 1976. The last case of smallpox in the United States occurred in 1949. An MMWR report in 1997 commemorating the 20th anniversary of the eradication of smallpox noted that smallpox vaccine and its eradication of smallpox disease were on the list of things that need be done only once in the history of the world (1).

The U.S. public health system is preparing for the potential use of smallpox (variola) virus as a bioterrorism agent. Although preparedness efforts have been ongoing since at least 1999 and a strategic plan for preparedness and response against biologic and chemical terrorism was published in April 2000 (2), the terrorist attacks against the United States on September 11, 2001, prompted extensive review of policies and procedures about potential acts of bioterrorism, especially the intentional release of smallpox virus. To enhance preparedness, the U.S. Department of Health and Human Services has contracted for production of enough smallpox vaccine for the entire U.S. population if vaccination becomes necessary, developed a plan for responding to a smallpox attack (, and is reviewing whether increased vaccination before an attack is warranted and how such a vaccination program would be implemented. A final U.S. policy on smallpox vaccination is pending. Additional information on smallpox is available at


  1. CDC. Smallpox surveillance---worldwide. MMWR 1997;46:990--4.
  2. CDC. Biological and chemical terrorism: strategic plan for preparedness and response. MMWR 2000;49(No. RR-4).

Use of trade names and commercial sources is for identification only and does not imply endorsement by the U.S. Department of Health and Human Services.

References to non-CDC sites on the Internet are provided as a service to MMWR readers and do not constitute or imply endorsement of these organizations or their programs by CDC or the U.S. Department of Health and Human Services. CDC is not responsible for the content of pages found at these sites. URL addresses listed in MMWR were current as of the date of publication.

Disclaimer   All MMWR HTML versions of articles are electronic conversions from ASCII text into HTML. This conversion may have resulted in character translation or format errors in the HTML version. Users should not rely on this HTML document, but are referred to the electronic PDF version and/or the original MMWR paper copy for the official text, figures, and tables. An original paper copy of this issue can be obtained from the Superintendent of Documents, U.S. Government Printing Office (GPO), Washington, DC 20402-9371; telephone: (202) 512-1800. Contact GPO for current prices.

**Questions or messages regarding errors in formatting should be addressed to

Page converted: 10/24/2002


Safer, Healthier People

Morbidity and Mortality Weekly Report
Centers for Disease Control and Prevention
1600 Clifton Rd, MailStop E-90, Atlanta, GA 30333, U.S.A


Department of Health
and Human Services

This page last reviewed 10/24/2002