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Will vaccine help curb new Ebola outbreak in the DRC?

Ebola has surfaced in a remote part of the Democratic Republic of the Congo (DRC), the first outbreak of the disease since the West African epidemic that killed more than 11,000 people before it came to an end 2 years ago. A vaccine proved its worth in that epidemic—which hit major cities—but it is still awaiting approval from regulatory agencies, and the DRC government has yet to request the vaccine’s use to quell this outbreak.

As of 14 May, there were 19 people suspected of having been infected with the virus, and three of them have died, according to Eugéne Kabambi, an emergency communications officer for the World Health Organization (WHO) who is based in Kinshasa. The National Institute for Biomedical Research in Kinshasa has confirmed with the polymerase chain reaction test that blood samples from two of the cases were positive for Ebola-Zaïre virus. An additional 125 people are believed to have had contact with infected people and are under surveillance, according to Kabambi.

The outbreak began 22 April in the Nambwa Health Center of the Bas Uélé province, which is in the northern region of the DRC that borders the Central African Republic.

WHO reports issued 13 May (here and here) noted that the first case, a 45-year-old man (initially described as 39 years old) first presented to a health facility with bloody urine, diarrhea, nose, and vomit. He had to travel by motorbike across the large province to reach a hospital in Likati, says Susan Shepherd, a clinician with a humanitarian aid group, ALIMA, which has a team in the DRC and plans to respond to the outbreak. (This was first reported by The Washington Post.) He also was transported in a taxi. According to WHO, the man had died by the time he reached the hospital in Likati. The people who transported him also became ill and died.

Shepherd, who spoke from ALIMA’s headquarters in Dakar, says the first victim’s blood was drawn 1 May. It took 10 days for the man’s sample to reach Kinshasa, which is about 1400 kilometers from Likati. (The DRC has no roads that span the country and long-distance travel largely is restricted to river boats and private airplanes.) WHO notes that it “was informed” about the cluster of cases on 9 May and the confirmation of the 45-year-old man occurred 2 days later.

Marie-Paule Kieney, an assistant director-general at WHO in Geneva, Switzerland, who played a central role during the West African epidemic, says Merck, the maker of the vaccine that appeared to work in a trial held in Guinea in 2015, is ready to provide the product if necessary. “Discussions are ongoing with the government on whether vaccination should be undertaken or not,” Kieney says. “The outbreak is very small, so it may be stopped through containment only.”

Traditional containment efforts include isolating and confirming cases, providing protective gear for health care workers, using safe burial procedures, and educating the public about how to reduce their risks.

One person helping with the response, who asked not to be identified because of the political sensitivity created by the outbreak, said some were deeply frustrated that a decision has yet to be made about whether to use the vaccine. “If it were up to me I’d already be using it,” the person says. “It’s hard to dream up a rationale for not using the vaccine as quickly as possible.”

Plenty of the Merck vaccine exists, though its experimental status would require what’s known as an “Expanded Access” study protocol to be approved by national and international regulatory bodies before it could be shipped to the DRC. WHO has some 10,000 doses in Geneva, leftover from the West Africa outbreak, sources tell ScienceInsider, and Merck has some 700,000 doses on ice in the United States.

Before the DRC outbreak became known, experts who serve on WHO’s Strategic Advisory Group of Experts on Immunization (SAGE) recommended that the Merck vaccine “be promptly deployed” if the Ebola-Zaïre strain of the virus surfaces. Experts attending a 25–27 April SAGE meeting in Geneva also suggested that an Expanded Access study “be implemented promptly after the confirmation of a case” and that the vaccine be used in the same “ring vaccination” strategy that worked in Guinea, which gave shots to people (including health care workers) who were in close contact with each confirmed case.

When asked about the vaccine’s status, a WHO spokesperson in Geneva wrote to ScienceInsider in an email on 15 May that “WHO and partners are completing the epidemiological investigation to better understand the extent of the current outbreak and who are potentially at risk of Ebola.” The spokesperson emphasized that “preparations are being accelerated to ensure that vaccine and equipment be available on site” and that the “appropriate ethical and regulatory authorisation” was being sought. WHO’s Kabambi noted on 15 May that the DRC’s Ministry of Health “has provided a comprehensive National Plan of Response, but still lacks a detailed budget to move forward.”

Doctors Without Borders (MSF)—which led the initial health care response in West Africa during the last outbreak—have 14 people en route to Likati, including doctors, nurses, logisticians, water and sanitation experts, health promoters, and an epidemiologist. Another 10 people from the DRC’s Ministry of Health also left Kinshasa on Saturday for Likati. A cargo plane with 15 tons of medical and logistical supplies flew to Kisangani, and MSF says it expects all people and equipment to arrive in Buta by tomorrow. It is a rugged 150 kilometers from Buta to Likati.

MSF’s Armand Sprecher, an experienced Ebola clinician based in Brussels, says the group would like to make the vaccine available to its workers, but he stresses that they know how to protect themselves from the virus. “We’ve been managing Ebola outbreaks for 25 years in the absence of a vaccine,” Sprecher says. “Even with folks vaccinated, we’ll have the same risk-management plan in place. It’s not like an either/or thing.”

He notes, too, that vaccinated people often spike a slight fever, which could be confused for Ebola, which means health care workers ideally would be vaccinated several days before they arrive. ALIMA’s Shepherd agrees. “The first task is to get supplies to health workers so they can protect themselves,” she says.

Sprecher’s main concern is that the vaccine be made available for people living in the Likati Health Zone. “It may be a big help in shutting down transmission,” he says.

Sprecher says it’s always difficult to move unlicensed medicines into countries. “I’ve been part of the process,” Sprecher says. “As hard as you push, things move only as fast as the most tardy organization.”

The first documented Ebola outbreak, which occurred in 1976, hit Yambuku in the DRC. The country since has had six other outbreaks, and the worst one was contained with only 315 cases of the highly lethal disease.