The World Health Organization (WHO) and its partners are continuing their programmes against yellow fever outbreaks even though the epidemic, first reported in January 2016, appears to be declining, with no new cases confirmed in the last few weeks.
WHO in a statement said it expects that more than 17 million additional people will be vaccinated in Angola and Democratic Republic of the Congo (DRC) before the rainy season starts in September.
It noted that, vaccination is the most important means of preventing the disease, stating that, in high-risk areas where vaccination coverage is low, prompt recognition and control of outbreaks using mass immunization is critical for preventing epidemics.
The statement also said that it is important to vaccinate most (80 per cent or more) of the population at risk to prevent transmission in a region with a yellow fever outbreak.
The UN health agency said that, coordination also ensured that a response to the outbreak has been timely, with the first shipment of vaccines to Angola arriving within five days of the country making a request to the ICG.
WHO speculated that the rise in yellow fever cases is due to the unusual severity of El Nino, which has led to a higher than usual density of the mosquitoes that transmit the disease.
Yellow fever is an acute viral haemorrhagic disease transmitted by infected Aedes mosquitoes.
Its symptoms of include fever, headache, jaundice, muscle pain, nausea, vomiting and fatigue.
A small proportion of patients who contract the virus develop severe symptoms and approximately half of those die within seven to 10 days.