Brazil’s health authority has moved to expand its yellow fever vaccine stockpile by 11.5 million doses to tackle the country’s worst outbreak of the mosquito-borne disease since 2000.
Officials sent the order to Bio-Manguinhos, a unit of Brazilian research organization Fiocruz. The extra doses will be added to routine stocks that are sent out to Brazilian states each month.
As of Jan. 26, the country’s Ministry of Health has recorded 550 suspected cases of yellow fever this season and 40 confirmed deaths. A total of 455 cases remain under investigation. Together, the figures make this year's outbreak the most serious in Brazil in 16 years.
A vaccine known as 17D is the only commercially available yellow fever shot. Besides Bio-Manguinhos, three other entities produce it: Sanofi Pasteur, the Institut Pasteur Foundation in Dakar and a Russian state-owned manufacturer.
Back in late 2015, a yellow fever outbreak detected in Angola triggered a global vaccine shortage, and an emergency stockpile was “completely depleted" by April 2016. Facing that shortage, experts proposed in a Lancet article that the World Health Organization consider further lowering the required dosage to stretch supplies.
According to data last updated by the WHO in October 2016, the international agency has sent more than 30 million yellow fever vaccine doses to Angola, Democratic Republic of the Congo and Uganda since that outbreak. Some of those doses were provided by Bio-Manguinhos.
Brazil's yellow fever outbreak comes about a year after the country suffered from an explosive outbreak of Zika virus, also spread by mosquitoes. Now, Zika vaccine development continues, even though it's no longer regarded as an international emergency by WHO. As part of that effort, Fiocruz is collaborating with Sanofi Pasteur and the Walter Reed Army Institute of Research on a Zika shot.