The World Health Organization (WHO) has warned that there may be a shortage of yellow fever vaccine if there are any new outbreaks of the viral haemorrhagic disease this year.
“The vaccine supply, that is normally sufficient, may become really stretched if we have more outbreaks in the coming months,” Sylvie Briand, director of pandemic and epidemic diseases at the WHO, told reporters at a news conference on 10 May 2016.
According to the WHO, since the current outbreak of yellow fever began in Angola in December 2015, Angola has reported 2,267 suspected cases and 293 deaths, the Democratic Republic of Congo has reported two confirmed local transmissions and 44 probable cases (of which 41 have been confirmed), while Uganda has reported 51 suspected cases and three deaths. China has confirmed 11 imported cases from Angola, and Kenya has confirmed two imported cases from Angola.
Briand stressed that the WHO is responding to current outbreaks “as an emergency”.
The yellow fever vaccine, which is 99% effective and provides lifelong protection, is the “most effective tool we have at the moment”, she added.
A small proportion of patients who contract the virus develop severe symptoms, such as bleeding from the mouth, nose, eyes or stomach, and around half of these patients die within 10 to 14 days, the WHO says.
The vaccine, which is currently available from four manufacturers, is effective ten days after immunisation. Global output is around 60 million to 70 million doses per year, of which 25 million to 30 million doses are used for routine immunisation, 30 to 35 million doses for catch up campaigns in endemic countries, and 6 million for the emergency stockpile.
The entire emergency stockpile was deployed to vaccinate the population of the Angolan capital Luanda (7.2 million people) in late January/early February 2016 with the shortfall made up by vaccine donations from Sudan and Brazil.
Briand said manufacturers have been asked “to scale-up” their production and noted that GAVI, The Vaccine Alliance, a global health partnership committed to increasing access to immunisation in poor countries, has donated more money to replenish the emergency stockpile.