By Sola Ogundipe
Limited supplies of the yellow fever vaccine is stalling full response efforts to the yellow fever outbreak in parts of Africa. It takes six months to develop the vaccine.
Confronted by acute shortage of vaccines to protect millions potentially at risk of yellow fever, public health officials are struggling to manage the disease outbreak in Angola and the Democratic Republic of Congo, even as worries that the virus could spread are making the rounds.
The prevailing yellow fever transmission has been explosive and has rapidly exhausted global emergency stockpile of at least six million vaccine doses. It is feared that a second outbreak in a densely populated country could deplete the dangerously low vaccine supply.
Currently, experts are anxiously watching the progress of the outbreak and are concerned it could spread to countries that have never faced large scale outbreaks of the virus before and therefore have little natural immunity. As a stop-gap measure aimed at providing at least some protection, the World Health Organization (WHO), is vaccinating14 million people against the disease in 8,000 locations by diluting the vaccine to one-fifth the dose.
Millions have already been vaccinated with a full dose of the protective yellow fever vaccine that provides lifelong protection, but as supplies have dwindled, health officials are implementing the emergency measure that involves diluting the vaccine further so that it will provide protection for one year.
Health experts say the current vaccination plan may be inadequate to protect enough people, hence they have warned that the virus could spread and possibly reach densely populated regions in Africa and Asia, where the disease could rapidly become endemic.
“Protecting as many people as possible is at the heart of this strategy. With a limited supply we need to use these vaccines very carefully,” said William Perea, Coordinator for the Control of Epidemic Diseases Unit at WHO. Yellow fever “transmission in 2016 has been explosive and rapidly exhausted the usual global emergency stockpile of at least six million vaccine doses.
But a second outbreak in a densely populated country could deplete the dangerously low vaccine supply. Since December 2015, the yellow fever outbreak has infected over 5,000 persons with over 400 deaths in Angola and the Democratic Republic of Congo. The disease is spread by mosquitoes, especially the Aedes aegypti mosquito that also spreads Zika virus.
Symptoms of yellow fever include fever, chills, severe headache, back pain and nausea; the virus has been fatal in approximately 20 percent of cases. Health officials are fighting the virus on two fronts, by treating people and reducing mosquito populations so it doesn’t spread across the continent or globe.
According to researchers from the Centers for Diseases Control and Prevention: “This epidemic in the three countries and its introduction to seven other countries illustrates how all countries are connected and that a threat in one country is a threat everywhere.”
It is believed that Yellow fever is “tenacious” and the number of cases in Africa is probably far higher than what had been reported. About 99 per cent of people develop immunity within one month of vaccination with the Yellow fever vaccine, which is a live-virus vaccine that has been used for several decades. A single dose provides lifelong protection for most people.