The trial is focusing on health workers and individuals who have been exposed to the Ebola strain.

On Monday, Ugandan authorities initiated a clinical trial for a vaccine targeting the Sudan strain of Ebola, which has claimed one life in the outbreak declared last week. Health workers and individuals exposed to the virus are the focus of the trial, which began four days after Uganda confirmed the death of a nurse in the capital, Kampala.

On the same day, two additional cases were reported in the nurse’s relatives. Authorities are investigating the origin of the outbreak.

The trial is considered a significant step in public health emergency response and highlights the strength of global health collaboration, according to Matshidiso Moeti, the WHO director for Africa.

Ebola spreads through contact with the bodily fluids of an infected person or contaminated materials. Symptoms include fever, vomiting, diarrhea, muscle pain, and sometimes internal and external bleeding. The outbreak response faces additional challenges due to the highly mobile population of about 4 million in Kampala.

The nurse who died sought treatment at a hospital outside the capital before traveling to Mbale in eastern Uganda, where he was admitted to a public hospital. He also consulted a traditional healer. The Ministry of Health has identified at least 234 contacts linked to the outbreak.

Health authorities now have access to over 2,000 doses of a candidate vaccine against the Sudan strain, provided by IAVI.

This outbreak is the first since the Trump administration’s decision last week to withdraw from the UN health agency and suspend foreign assistance. Uganda has experienced multiple Ebola outbreaks, including one in 2000 that caused hundreds of deaths. Tracking contacts is crucial in preventing the spread of Ebola, which causes viral hemorrhagic fever.

A trial vaccine called rVSV-ZEBOV, used to vaccinate 3,000 people at risk during the 2018-2020 outbreak of the Zaire strain of Ebola in eastern Congo, was successful in controlling the disease’s spread there.

The confirmation of Ebola in Uganda adds to the series of viral hemorrhagic fever outbreaks in East Africa. Tanzania reported an outbreak of the Ebola-like Marburg disease last month, while Rwanda declared its own Marburg outbreak over in December.

The natural reservoir of the Ebola virus remains unknown, but scientists believe the first person infected in an outbreak likely contracted the virus through contact with an infected animal or by consuming its raw meat.

Ebola was first identified in 1976 in two simultaneous outbreaks in South Sudan and Congo, one of which occurred in a village near the Ebola River, giving the disease its name.