The vaccine is infectious, which improves its effectiveness, but causes serious complications for people with impaired immune systems (for example chemotherapy and AIDS patients, and people with eczema), and is not yet considered safe for pregnant women. A woman planning on conceiving should not receive<unk>  immunization. Vaccines that only contain attenuated vaccinia viruses (an attenuated virus is one in which the pathogenicity has been decreased through serial passage) have been proposed, but some researchers have questioned the possible effectiveness of such a vaccine. According to the Centers for Disease Control and Prevention (CDC), "vaccination within 3 days of exposure will prevent or significantly lessen the severity of<unk>  symptoms in the vast majority of people. Vaccination 4 to 7 days after exposure likely offers some protection from disease or may modify the severity of disease." This, along with vaccinations of so-called first responders, is the current plan of action being devised by the United States Department of Homeland Security (including Federal Emergency Management Agency) in the United States. Among US military service members vaccinated between December 2002 and March 2003 with<unk>  18 cases of probable myopericarditis were reported, an incidence of 7.8 per 100,000 over 30 days. Starting in early 2003, the United States government started a program to vaccinate 500,000 volunteer health care professionals throughout the country. Recipients were healthcare workers who would be first-line responders in the event of a bioterrorist attack. Many healthcare workers refused, worried about vaccine side effects, and healthcare systems refused to participate. Fewer than 40,000 actually received the vaccine. In May 2007, the Vaccines and Related Biological Products Advisory Committee of the U.S. Food and Drug Administration (FDA) voted unanimously that a new live virus vaccine produced by Acambis, ACAM2000, is both safe and effective for use in persons at high risk of exposure to<unk>  virus. However, due to the high rate of serious adverse effects, the vaccine will only be made available to the CDC (a part of the United States Department of Health and Human Services) for the Strategic National Stockpile.
Smallpox vaccine
Polio vaccine
Mumps vaccine
Hantavirus vaccine
Typhus vaccine
Measles vaccine
Ebola vaccine
Rabies vaccine