Uganda announced Thursday that it had received shipments of two more trial vaccines to test against a strain of Ebola responsible for dozens of deaths in the East African nation.

Since authorities declared an Ebola outbreak on September 20, Uganda has registered 142 confirmed cases and 56 deaths, but the spread has slowed in recent weeks, sparking hope that the epidemic could be on its way out.

The outbreak has been caused by the so-called Sudan strain of the virus, for which there is currently no vaccine.

But three candidate vaccines — one developed by Oxford University and the Jenner Institute in Britain, another from the Sabin Vaccine Institute in the United States, and a third from the International AIDS Vaccine Initiative (IAVI) — will be trialed in Uganda in the coming weeks.

On December 8, Uganda received its first shipment of doses from the Sabin Vaccine Institute.

The absence of active Ebola cases in recent days has held up the vaccine trials, according to international health experts working in Uganda.