The World Health Organization (WHO) has recommended a reduction in the dosage of yellow fever vaccine.

According to the global health body, a fifth (1/5)of the current dosage could be given during emergencies as a shortage of the vaccine looms. There have been concerns that the scale of the current outbreak in Angola and Democratic Republic Congo could force a shortage in vaccines.

As such the WHO is recommending ‘fractional dosing’; a short term measure to ensure that more people get vaccinated against the yellow fever virus especially because of fears that the outbreak would spread further. This means 0.1 millilitres would be used instead of 0.5 millilitres. WHO’s Strategic Advisory Group of Experts (SAGE) on Immunization found that using a fifth of the vaccine could lead to protection of up to a year or even longer.

According to Jon Abramson; the chair of SAGE, there is huge pressure for distribution of the vaccine.

“Yellow fever outbreaks in Angola, Democratic Republic of the Congo and Uganda are placing unprecedented demands on vaccine supply for emergency vaccination campaigns to control the spread of the disease. Right now we have enough vaccines in the global stockpile to cope with the ongoing outbreaks if there are no further extensions."

It is hoped that in a year’s time, the outbreak would have been greatly diminished while stockpiles of the vaccines are increased. The annual global stockpile of 6 million doses has been exhausted twice in this year alone.

Earlier this month, the Ghana Health Service announced that it would be stepping up its vaccination campaign efforts after cases were confirmed in parts of the Brong Ahafo and Volta Region.

Related: What is yellow fever?

Yellow fever is a serious viral infection common in tropical areas of the world including Africa, Central and South America. The WHO says 47 countries are “either endemic for, or have regions that are endemic for, yellow fever.” 34 of these are in Africa.

The virus is transmitted between people from the bite of infected mosquitoes; some of which breed near homes. Symptoms include fever, appetite loss, nausea, headache, fatigue, muscle pain and jaundice (yellowing of skin and eyes).

Half of those who contract the disease die within seven to ten days according to the WHO.

Vaccination and mosquito control measures are the most efficient ways to fight the disease.