Yellow fever known as "mosquito inspectors" fiercely worked to combat yellow fever throughout Rio by spraying, exterminating rats, improving drainage, and destroying unsanitary housing. Ultimately, the city's sanitation and renovation campaigns reshaped Rio de Janeiro's neighborhoods. Its poor residents were pushed from city centers to Rio's suburbs, or to towns found in the outskirts of the city. In later years, Rio's most impoverished inhabitants would come to reside in "favelas". During 1920–23, the Rockefeller Foundation’s International Health Board undertook an expensive and successful yellow fever eradication campaign in Mexico. The IHB gained the respect of Mexico’s federal government because of the success.
Yellow fever vaccine Yellow fever vaccine Yellow fever vaccine is a vaccine that protects against yellow fever. Yellow fever is a viral infection that occurs in Africa and South America. Most people begin to develop immunity within ten days and 99% are protected within one month of vaccination, and this appears to be lifelong. The vaccine can be used to control outbreaks of disease. It is given either by injection into a muscle or just under the skin. The World Health Organization (WHO) recommends routine immunization in all countries where the disease is common. This should typically occur between nine and twelve months