US researchers warn that the yellow fever outbreak in Angola may become a global emergency because of a shortage in the yellow fever vaccine. This mosquito borne viral illness has already caused deaths in 277 people in Angola since December. Angola has a population of 6 million. The World Health Organization (WHO) says that almost a quarter of the population has been vaccinated but the vaccine stock piles ran out last month. Already reports are coming from neighboring countries that the virus has infected people in Kenya, Democratic Republic of Congo and Zambia.
It usually takes about 6 months to produce the vaccine and this time-lag can prove to be significant when there is a large outbreak. Drug manufacturers usually produce just enough vaccine for routine immunization but not for such emergencies. This crisis in Angola can quickly become a global problem if the virus starts to spread outside of Africa.
The WHO is now coordinating efforts to mobilize funds and spearhead emergency vaccine production. Angola is a poor country and with its rudimentary healthcare facilities, it is expected that many more fatalities will occur.
Yellow fever is a virus spread by mosquitoes. In some people it is known to cause liver and kidney damage resulting in severe bleeding and jaundice. It is spread by the Aedes Aegypti mosquito, which is the same species that is known to spread the Zika virus. Yellow fever has always been endemic in many tropical regions of South America and Africa. According to recent data there are about 84,000 to 170,000 cases and nearly 60,000 deaths due to yellow fever annually. However, over the past decade since the introduction of the vaccine, the number of cases has been declining.
The yellow fever vaccine is administered as a single dose, is affordable, safe and highly effective. A single dose of the vaccine is sufficient for long term immunity and life-long protection against yellow fever. In most cases, a booster shot is never needed. After administration of the vaccine, effective immunity develops within 4 weeks in close to 99% of people.
It is believed that the vast majority of people in Angola never got the vaccine either due to lack of education or inability to afford it. There is no drug to treat this infection except intense medical supportive therapies. Before the vaccine was introduced, yellow fever resulted in high mortality rates.