In January 2017, an outbreak of yellow fever took off in rural Minas Gerais, Brazil. Since then, nearly 800 lab-confirmed cases and a case fatality rate of 34% have been reported, making this outbreak the largest Brazil has faced in recent memory.
One of the primary concerns among epidemiologists and entomologists over the last several months has been the possibility of urbanized transmission via the vector Aedes aegypti (which can then lead to an explosive growth in cases). Thankfully, there isn’t any evidence that this is happening at present, and there’s hope that it’ll stay that way long enough for the Southern Hemisphere’s winter season to put an end to Brazil’s steady stream of cases.
From what I can tell, massive vaccination campaigns – especially those taking place in in Brazil’s urban epicenters – may have been critical to the prevention of urbanization. Since the beginning of the outbreak, a whopping 25 million doses of yellow fever vaccine have been distributed – capturing more than 10% of Brazil’s entire population.
Unfortunately, given the fact that we are currently in the midst of a global yellow fever vaccine shortage, I can’t help but wonder: will we get so lucky during the next outbreak? Considering double digit case fatality rates, as well as widespread (and ever-growing) viability of urban virus transmission, I personally believe that replenishing the global yellow fever vaccine stockpile should be treated as a priority.
(Whether or not it will be? I guess we’ll have to wait and see.)