The nation's Ministry of Health recommended that the Argentines travel to any of these twenty Brazilian states (Rora, Amapá, Amazonas, Pará, Acre, Rondónia, Mato Grosso, Mato Grosso Do Sul, Maranhao, Tocantins, Goiás, Sáo Paulo, Paraná, Santa Catarina , Rio Grande Do Sul, Piaui (Western and Southern), Bahia, Minas Gerais, Espíritu Santo and Rio de Janeiro) that have been vaccinated against yellow fever at least 20 days prior to departure.
This recommendation has caused unusually increasing demand for doses of these vaccines in the recent days of Buenos Aires, In Misiones, although there was an increase in demand for a yellow fever vaccine, it was not so significant. One of the reasons is that 96% of the population of the province is already immunized against this disease, It is worth noting that the vaccination certificate is not a requirement for entry into Brazil. Although those who travel over Paraguay to or from North Brazil will have to accede to the vaccine, at the orders of Paraguayan authorities.
Every ten years or just once?
Prior to 2016, it has been recommended to increase the yellow fever vaccine every ten years. However, since July of that year, the World Health Organization (WHO) decided that the period of validity of all vaccination certificates against yellow fever, including those that were already issued and new, should last up to 10 years throughout the life of the vaccinated person.
WHO provides information to tourists about the worry they need to take to avoid spreading yellow fever and other vector diseases when visiting countries with a risk of transmission (Https://www.argentina.gob.ar/sites/default/files/0000001383cnt-2018-11_ith-country-list-nov-2018.pdf). For tourists for nine months who want to visit Argentina, WHO recommends that they be vaccinated against yellow fever if their destination is the Corrientes and Misiones provinces.
In Brazil, the area of yellow fever has expanded in the last three years: it started in the north and spread from east to south, mainly affecting central and western states. Registered cases in 2016, 2017 and 2018 have exceeded reported cases in the last 50 years.