WHO officials at Kagadi Hospital in Uganda's western Kibale district. (Photo: Isaac Kasamani/AFP)

Sixty-three confirmed and possible cases have been reported in the Ebola outbreak in Uganda, while 29 were confirmed dead, the World Health Organization said Wednesday.

The vaccines that were used to control the latest outbreaks in the neighboring Democratic Republic of Congo (DRC) were not efficient in confronting the type of Ebola virus that is spreading in Uganda, according to WHO chief Tedros Adhanom Ghebreyesus, who lamented that the outbreak that was declared by the government in Uganda two weeks ago is taking a deadly toll on health workers.

"So far, 63 confirmed and probable cases have been reported, including 29 deaths," Tedros said at a press conference in Geneva, adding, "Ten health workers have been infected and four have died. Four people have recovered and are receiving follow-up care."

Health Minister Jane Ruth Aceng Ocero said that an anesthetist aged 58 had died of Ebola early Wednesday.

"The late Margaret (Nabisubi) is the fourth health worker we have lost in the current Ebola outbreak," he said on Twitter, after a Tanzanian doctor, a health assistant, and a midwife died.

The WHO chief emphasized the effects of delays in detecting an Ebola outbreak and focused on the vaccines being developed in the country, noting that two could begin clinical trials in the coming weeks, as they are currently ending regulatory and ethics approvals from the government.

The WHO is supporting the government in its response to the outbreak that was reported in four districts so far, Tedros said, adding that the United Nations health agency released $2 million from its contingency fund for emergencies and is collaborating with partners by sending additional specialists, resources, and supplies.

Lockdowns will not be imposed, according to Ugandan President Yoweri Museveni who said last week that there was "no need for anxiety".