This report updates CDC's recommendations for using yellow fever (YF) vaccine (CDC. Yellow fever vaccine: recommendations of the Advisory Committee on Immunizations Practices: MMWR 2002;51[No. RR-17]). Since the previous YF vaccine recommendations were published in 2002, new or additional information has become available on the epidemiology of YF, safety profile of the vaccine, and health regulations related to the vaccine. This report summarizes the current epidemiology of YF, describes immunogenicity and safety data for the YF vaccine, and provides recommendations for the use of YF vaccine among travelers and laboratory workers. YF is a vectorborne disease resulting from the transmission of yellow fever virus (YFV) to a human from the bite of an infected mosquito. It is endemic to sub-Saharan Africa and tropical South America and is estimated to cause 200,000 cases of clinical disease and 30,000 deaths annually. Infection in humans is capable of producing hemorrhagic fever and is fatal in 20%-50% of persons with severe disease. Because no treatment exists for YF disease, prevention is critical to lower disease risk and mortality. A traveler's risk for acquiring YFV is determined by multiple factors, including immunization status, location of travel, season, duration of exposure, occupational and recreational activities while traveling, and local rate of virus transmission at the time of travel. All travelers to countries in which YF is endemic should be advised of the risks for contracting the disease and available methods to prevent it, including use of personal protective measures and receipt of vaccine. Administration of YF vaccine is recommended for persons aged >or=9 months who are traveling to or living in areas of South America and Africa in which a risk exists for YFV transmission. Because serious adverse events can occur following YF vaccine administration, health-care providers should vaccinate only persons who are at risk for exposure to YFV or who require proof of vaccination for country entry. To minimize the risk for serious adverse events, health-care providers should observe the contraindications, consider the precautions to vaccination before administering vaccine, and issue a medical waiver if indicated.
