MercoPress. South Atlantic News Agency

Yellow fever in Brazil: extended vaccine fractionation because of lack of supplies

Preliminary data from Rio de Janeiro and São Paulo shows that 3.95 million people were vaccinated, 3.6 million with fractional doses and 356,800 with standard doses.

The Brazilian Ministry of Health has reported that from July 1, 2017 to February 15 of this year, 409 cases of yellow fever were confirmed in the country, 183 in São Paulo, 157 in Minas Gerais, 68 in Rio de Janeiro and 1 in the Federal District. There were also 118 deaths throughout the country, 44 in Minas Gerais, 46 in São Paulo, 27 in Rio de Janeiro and one death in the Federal District.

Preliminary data from the states of Rio de Janeiro and São Paulo shows that 3.95 million people were vaccinated, 3.6 million with fractional doses and 356,800 with standard doses.

“The vaccine is the most effective measure to fight the disease and prevent cases and deaths. That is why it is necessary that all the population that lives in the municipalities where the campaign is taking place should try to get vaccinated. The yellow fever virus has affected people living in areas near forests that have never been vaccinated against yellow fever, that is, susceptible to the disease, “warned Health Minister Ricardo Barros.

The forecast is that 20.5 million people will be vaccinated in the Southeast, with 10.3 million being vaccinated in 54 municipalities in São Paulo and 10 million in 15 municipalities in Rio de Janeiro.

In Bahia, the yellow fever vaccine fractionation campaign starts this Monday. The state intends to vaccinate 3.3 million people in 8 counties.

Adoption of vaccine fractionation is a preventive measure recommended by the World Health Organization (WHO) when there is an increase in epizootic and cases of wild yellow fever in an intense way, with risk of disease spread in cities with a high population index. The fractionated dose has shown the same protection as the standard dose. Ongoing studies have already shown protection for at least eight years and further research will continue to assess protection after this period.

The Brazilian Ministry of Health reiterates that there is no confirmed record of urban yellow fever in the country and there is also no record of Aedes aegypti mosquitoes infected with the yellow fever virus. All cases of yellow fever recorded in Brazil since 1942 are wild, including current ones, that is, the disease was transmitted by vectors that exist in forest environments (mosquitoes of the genus Haemagogus and Sabethes).

In addition, what characterizes the wild transmission, in addition to the species of the mosquito involved, is that the mosquitoes transmit the virus and also become infected from a wild host, in this case the monkey.