[4] Most people begin to develop immunity within ten days of vaccination and 99% are protected within one month, and this appears to be lifelong.

[4][5] Medical experts recommend vaccinating people most at risk of contracting the virus, such as woodcutters working in tropical areas.

[12] In affected areas, mosquito control methods have proven effective in decreasing the number of cases.

[23] In addition, there is a small risk of neurologic disease and encephalitis, particularly in individuals with compromised immune systems and very young children.

[30] The Canadian Medical Association published a 2001 CMAJ article entitled "Yellow fever vaccination: be sure the patient needs it".

[36] This nonfatal case occurred in a traveler from Spain who visited several West African countries in 1988".

[37] African tropical cultures had adopted burial traditions in which the deceased were buried near their habitation, including those who died of Yellow fever.

This led to a lasting misperception, first by colonial authorities and foreign medical experts, that Africans have a "natural immunity"[39] to the illness.

[40] The first modern attempts to develop a yellow fever vaccine followed the opening of the Panama Canal in 1912, which increased global exposure to the disease.

[41] The Japanese bacteriologist Hideyo Noguchi led investigations for the Rockefeller Foundation in Ecuador that resulted in a vaccine based on his theory that the disease was caused by a leptospiral bacterium.

[citation needed] Another vaccine was developed from the "French strain" of the virus, obtained by Pasteur Institute scientists from a man in Dakar, Senegal, who survived his bout with the disease.

Scientists at the Rockefeller Foundation developed another vaccine derived from the serum of an African named Asibi in 1927, the first isolation of the virus from a human.

[4] Theiler's vaccine was responsible for the largest outbreak of hepatitis B in history, infecting 330,000 soldiers and giving 50,000 jaundice between 1941 and 1942.

[49] In 1941, researchers at Rocky Mountain Laboratories developed a safer alternative, an "aqueous-base" version of the 17D vaccine using distilled water combined with the virus grown in chicken eggs.

[56] The initiative was supported by the Gavi Alliance, a collaboration of the WHO, UNICEF, vaccine manufacturers, and private philanthropists such as the Bill & Melinda Gates Foundation.

[58][59] Two other manufacturers supply domestic markets: Wuhan Institute of Biological Products in China and Sanofi Pasteur in the United States.

[63] The outbreak of yellow fever in Angola and the Democratic Republic of Congo in 2016 has raised concerns about whether the global supply of the vaccine is adequate to meet the need during a large epidemic or pandemic of the disease.

[64] Routine childhood immunization was suspended in other African countries to ensure an adequate supply in the vaccination campaign against the outbreak in Angola.

[65] Emergency stockpiles of vaccine diverted to Angola, which consisted of about 10 million doses at the end of March 2016, had become exhausted,[58][66] but were being replenished by May 2016.

[70] On 17 June 2016, the WHO agreed to the use of 1/5 the usual dose as an emergency measure during the ongoing outbreak in Angola and the DR Congo.