American's stocks of yellow fever vaccines are set to run out this summer, the country's Centres for Disease Control and Prevention (CDC) has warned. In the body's Morbidity and Mortality Weekly report issued on Friday (28 April), it said it expected "a complete depletion of yellow fever vaccine available for the immunisation of US travellers by mid-2017".
According to the report by the CDC, the only US-approved vaccination had experienced manufacturing problems, which had led to the shortage.
Though the CDC and Food and Drug Administration (FDA) were said to be brokering a deal with multi-national pharmaceutical company Sanofi, allowing access to its vaccine division's drug at a limited number of sites, the shortage was not expected to be fully available until mid-2018.
Yellow fever is a serious viral infection, spread from human-to-human by the bites of infected mosquitoes, and can present with flu-like symptoms. In more serious cases, symptoms include jaundice, kidney failure or bleeding from the nose, mouth, eyes or stomach, which can be fatal, but it is preventable by vaccination.
Yellow fever vaccination is recommended for travel to large parts of Africa, as well as almost the entire continent of South America, excluding Chile and Argentina, and the edge of the continent's eastern coast. According to NHS advice, some countries deny entry to those without certification of vaccination while others will demand a certification to re-enter from an affected country without certification.
The report states that eight million US residents travelled to 42 countries in which the virus is endemic. However, there were only thought to be 10 cases of the virus in travellers returning to the US and Europe from an affected country.
The most recent, worst outbreak of the disease was in Angola in 2015, spreading to the Democratic Republic of Congo. It caused 965 cases between 2015 and 2017.
Yellow fever vaccinations last 10 years, after which they require a booster.