Analysis - In Congo outbreak, Ebola vaccine faces reality tests

FILE PHOTO: Congolese Health Ministry officials carry the first batch of experimental Ebola vaccines in Kinshasa, Democratic Republic of Congo May 16, 2018. REUTERS/Kenny Katombe/File Photo

LONDON, May 18 (Reuters) - An experimental Ebola vaccine to be deployed in an outbreak in Democratic Republic of Congo has conquered some major scientific hurdles in giving high protection, but it now faces extreme real-world tests including heat, humidity, language barriers and lack of roads.

Because it is not yet licensed, the Merck & Co vaccine has been offered to Congo under a "compassionate use" protocol agreed by national and international health and ethics authorities.