A type of vaccine derived from disease-causing viruses or bacteria that have been weakened under laboratory conditions. They will grow in a vaccinated individual, but because they are weak, they will cause either no disease or only a mild form.
Alert: Global Health Learning will go offline after May 31, 2025. You can use our Print feature to download course content for your reference. Log in, go to a course, click the Print link in the right sidebar. The course pages will be rolled together in one HTML page. You can copy/paste into a Google doc or save as HTML.