File photo shows passengers queue to be screened at Uganda's Entebbe International Airport on May 15, 2018. (Xinhua/Joseph Kiggundu)

KAMPALA, Dec. 20 (Xinhua) -- The World Health Organization (WHO) has donated another 3,000 doses of Ebola vaccine to immunize healthcare workers against the disease.

Yonas Tegegn Woldemariam, WHO Country Representative, said on Tuesday that the extra doses would extend the vaccination exercise to 20 high risk districts.

He was speaking at a meeting to discuss the country's state of preparedness against the disease, which is ravaging communities in neighboring eastern Democratic Republic of Congo.

Ruth Aceng, minister of health, thanked partners and donors for their continued support to Uganda's preparedness response to Ebola, despite the country not having the disease.

WHO in partnership with the ministry of health on Nov. 25 launched an Ebola vaccination exercise in which it provided the initial 2,100 doses of experimental Ebola vaccine.

According to ministry figures, more than 2,000 health workers have been vaccinated against Ebola in the high risk districts.

The Ebola virus is highly contagious and causes a range of symptoms including fever, vomiting, diarrhea, generalized pain or malaise and in many cases internal and external bleeding.

Mortality rates of Ebola fever, according to WHO, are extremely high, with the human case fatality rate ranging from 50 percent to 89 percent, depending on viral sub-type.