Smallpox and biological warfare: the case for abandoning vaccination of military personnel

Vaccines for viral diseases with dermatologic manifestations

Vaccines against infectious diseases have been available since the 1800s, when an immunization strategy against smallpox developed by Jenner gained wide acceptance. Until recently, the only vaccination strategies available involved the use of protein-based, whole killed, and attenuated live virus vaccines. These strategies have led to the development of effective vaccines against a variety of diseases with primary or prominent cutaneous manifestations. Effective and safe vaccines now used worldwide include those directed against measles and rubella (now commonly used together with a mumps vaccine as the trivalent MMR), chickenpox, and hepatitis B. The eradication of naturally occurring smallpox remains one of the greatest successes in the history of modern medicine, but stockpiles of live smallpox exist in the United States and Russia. Renewed interest in the smallpox vaccine reflects concerns about a possible bioterrorist threat using this virus. Yellow fever is a hemorrhagic virus endemic to tropical areas of South America and Africa. An effective vaccine for this virus has existed since 1937, and it is used widely in endemic areas of South America, and to a lesser extent in Africa. This vaccine is recommended once every 10 years for people who are traveling to endemic areas. Advances in immunology have led to a greater understanding of immune system function in viral diseases. Progress in genetics and molecular biology has allowed researchers to design vaccines with novel mechanisms of action (eg, DNA, vector, and VLP vaccines). Vaccines have also been designed to specifically target particular viral components, allowing for stimulation of various arms of the immune system as desired. Ongoing research shows promise in prophylactic and therapeutic vaccination for viral infections with cutaneous manifestations. Further studies are necessary before vaccines for HSV, HPV, and HIV become commercially available.

Biological warfare and infection control

Though many agents have been proposed as potential biological weapons, the feasibility of biological warfare is largely a matter of conjecture. The unpredictable and indiscriminate devastation caused by natural epidemics during wartime should warn us of the dangers of employing microbes as weapons.

Preventing secondary infections among HIV-positive persons

Secondary infectious diseases contribute substantially to morbidity and mortality of people infected with human immunodeficiency virus (HIV). The authors developed comprehensive, practical recommendations for prevention of infectious complications in HIV-infected people. Recommendations are concerned with the pathogens that are more common or more severe in HIV-infected people. Several infectious complications can be prevented by avoiding ingestion of contaminated food or water. Zoonoses can be prevented by precautions to be taken in contacts with animals. The risk of several fungal diseases can be reduced if activities likely to lead to inhalation of spores are avoided. HIV-infected people should be advised how to lower adverse health effects of travel, especially international travel. The potential for infectious complications of sexual activity and illicit drug use should be stressed, and recommendations to reduce the risk are discussed. Recommendations for use of vaccines in HIV-infected people are reviewed. Blood CD4+ lymphocyte concentrations, tuberculin skin testing, Toxoplasma serology, and sexually transmitted disease screening should be performed in certain subsets of HIV-infected people. Guidelines for chemoprophylaxis against Pneumocystis carinii and tuberculosis are presented. Recent data suggest that intravenous immunoglobulin therapy may prevent bacterial infections in HIV-infected children.

Human poxvirus infection after the eradication of smallpox

There occurred during the planning and publication of this review: the twentieth anniversary of the start of the intensified WHO Smallpox Eradication Campaign and the tenth anniversary of the last endemic case of smallpox; debate about the fate of smallpox virus and possibly its irrevocable destruction; claims that mass smallpox vaccination campaigns may have helped the spread of AIDS in Africa; publication of the definitive account of Smallpox and its Eradication (Fenner et al. 1988), and the closure of the WHO Smallpox Eradication Unit (SEU). It is therefore perhaps an appropriate moment to assess the current status of human poxvirus infections and their epidemiology; this review concentrates on those viruses antigenically related to smallpox (i.e. orthopoxviruses).