Stretching the supply to meet a growing demand.
Next week, people in Kinshasa, the capital of the Democratic Republic of the Congo (DRC), will be vaccinated against yellow fever using one fifth of the normal dose in an attempt to stretch the short supply of the vaccine for the city’s 10 million residents.
The DRC is endemic for yellow fever and regularly experiences outbreaks. But unusually high transmission rates in 2016 — possibly attributed to the severe El Niño, which led to high densities of the mosquitos that transmit yellow fever — along with purported mismanagement of the vaccine supply, has depleted the World Health Organization’s (WHO) emergency stockpile of 6 million doses in record time.
Although WHO has replenished its stockpile with 5 million new doses, the Congolese government is concerned that the 1.7 million doses it has received will still fall short. To avoid running out, they will begin diluting their doses to 0.1 milliliters, instead of the usual 0.5 milliliters.
Yellow fever is not highly contagious and can be prevented with vaccines. Infection usually causes fever and muscle pain, from which patients typically recover after several days. But about 15 percent of cases are more severe, with a returning fever accompanied by liver damage. These patients are at risk of internal bleeding, and about half of them die.
According to WHO, at least 2,000 suspected cases of yellow fever have been reported in DRC this year, including 95 deaths.
Whether the reduced dosage will safeguard against the disease remains to be seen. A study conducted in the Netherlands found that yellow fever vaccine diluted five-fold was as effective as the standard dosage.