LONDON — The World Health Organization on Monday announced Congo will start using a second experimental Ebola vaccine, as efforts to stop the deadly outbreak are stalled and Doctors Without Borders criticizes vaccination efforts to date.

Since this outbreak was declared in August 2018, more than 200,000 people have received doses of a vaccine made by Merck which will continue to be used in Congo. The UN health agency in a statement said the second vaccine, made by Johnson & Johnson, will be used from October in areas where Ebola is not actively spreading.

Using the Johnson & Johnson vaccine “will ensure that we have potentially an additional tool to prevent the expansion of the outbreak,” said Matshidiso Moeti, WHO’s Africa director.

So far, more than 3,030 people have been sickened by the Ebola virus in this outbreak, the second-worst in history and more than 1,990 have died.

The question of whether the Johnson & Johnson experimental vaccine should be used was at the center of a dispute between Congo’s former health minister, Dr. Oly Ilunga and global health officials. Ilunga had insisted Congo would not use the vaccine because he said it wasn’t sufficiently tested and would create confusion.

He resigned as the health minister in July after the president replaced him as the head of Congo’s Ebola response team. In his resignation letter, Ilunga criticized the “strong pressure exercised in recent months” to use the Johnson & Johnson vaccine.

Separately, Doctors Without Borders is seeking an independent committee to oversee Ebola vaccination efforts, similar to those that have been formed internationally to respond to outbreaks of meningitis, yellow fever and cholera.

The medical charity said greater transparency is needed and alleged that WHO is “restricting the availability” of the Merck vaccine in the field. Doctors Without Borders, also known by its French acronym, MSF, said the approximately 225,000 people vaccinated so far is “largely insufficient” and that between 450,000 and 600,000 people should have been immunized by now.

“Not enough people are getting the vaccine because of some arbitrary rules that haven’t been made clear,” Dr. Natalie Roberts, emergency coordinator for MSF, told The Associated Press.

She said restricting the vaccine to people who are known contacts of Ebola cases is problematic. “It comes down to very local control, when every morning it’s someone from WHO who decides who is going to be vaccinated and how many vials to open,” she said. “Trying to restrict eligibility for a vaccine for a disease that everybody is afraid of is just not going to work.”

MSF has described WHO’s strategy as “like giving firefighters a bucket of water to put out a fire, but only allowing them to use one cup of water a day.”

WHO spokesman Tarik Jasarevic said in an email that the limited number of Ebola vaccines needs to be used sparingly.

“If all doses were sent to (Congo), there would be no reserves available to respond should cases emerge in any of the high-risk neighboring countries,” he said. “That would jeopardize an effective, speedy response in those high-risk countries.” Beyond Congo, cases have been confirmed in Uganda and some health workers in Rwanda and South Sudan have been vaccinated preventively.

Jasarevic said an international committee like the one called for by MSF is only used for licensed vaccines; both Ebola vaccines remain experimental and have not been approved by any regulatory agencies.

“When the vaccine is licensed, this would be an appropriate mechanism for managing supply of the vaccine,” he said.

Roberts said the number of people vaccinated so far is ultimately a damning assessment of response efforts.

“If you had said at the beginning of the outbreak that we were going to vaccinate this many people, you would assume the outbreak would be over by now,” she said. “But clearly the right people were not vaccinated.”