The vaccine is supposed to complement the Merck vaccine which has been administered to 250,000 people since the 2018 Ebola outbreak and will be administered to an additional 50,000.
Health authorities in the Democratic Republic of Congo have introduced a new Ebola vaccine produced by Johnson & Johnson, aid group Doctors Without Borders (MSF) said on Thursday, to help combat the world's second-worst outbreak of the virus on record.
The new vaccine, produced by a Belgian subsidiary of Johnson & Johnson, will be administered to about 50,000 people over four months, the charity said. The campaign will take place in Goma, a city of two million on the Rwandan border, MSF said.
Over 250,000 people, many of them frontline health workers, have been immunised with another anti-Ebola vaccine in a programme begun last year.
The epidemic began in August 2018 in the province of North Kivu before spreading to neighbouring Ituri and South Kivu – a remote and largely lawless region bordering Uganda, Rwanda and Burundi.
The notorious haemorrhagic virus has so far killed 2,193 people, according to the latest official figures.
The outbreak is second only to the 2013-16 West African outbreak that killed more than 11,300.
The new vaccine has passed clinical trials but has never been tested in a real-world setting.
The vaccine, which requires two injections eight weeks apart, will be rolled out alongside another manufactured by Merck, which only requires a single shot.
"The introduction of a second vaccine is not meant to replace [Merck's] vaccine, but to complement it and hopefully provide us with an additional tool in the fight against future Ebola outbreaks," said John Johnson, who is leading the project for MSF.
The Merck shot is being deployed in a strategy known as "ring vaccination", which aims to control Ebola by identifying and offering the vaccine to contacts of those likely to be infected.
The plan with the addition of the J&J vaccine is to extend protection by providing it to "targeted at-risk populations" in areas where the disease is not yet being actively transmitted, according to the World Health Organization (WHO).
Four cases of the disease were recorded in Goma this year, but no new cases have been reported in the lakeside city since August.
Some Congolese health officials have criticised the J&J vaccine on the grounds that it has not been properly tested, although it has passed phase I and II clinical trials and been endorsed by the WHO.