China is making a bid to use its Ebola vaccine in the Democratic Republic of the Congo. It’s a move that could further complicate efforts to test a crowded field of vaccines and therapies in the context of a waning outbreak.

The head of the Chinese Center for Disease Control and Prevention (CDC), Gao Fu, is reported to have said that a team of experts will travel to the DRC on Friday, bringing with them an unspecified number of doses of vaccine.

“We will seek to use the Chinese developed vaccine there to help with control and prevention of the disease, but for the present the vaccines will likely only cover Chinese living in Congo,” Gao is reported as saying in China Daily.

The DRC health ministry’s daily Ebola update on Thursday noted that only one Ebola vaccine has been approved for use in the country at this time, and that is the vaccine being developed by Merck.  

Jessica Ilunga, a spokesperson for Health Minister Dr. Oly Ilunga, said there has not been an official request by the Chinese to use the vaccine. Any decisions on approving additional vaccines would have to be made by two government advisory committees, she said. One committee studies the science behind the products while the other looks at the ethics of using them.

The World Health Organization’s vaccines advisory committee has recommended that until there is a fully licensed Ebola vaccine, Merck’s experimental vaccine should be used in outbreaks. That vaccine is given in one dose and it triggers a rapid immune response – characteristics that are needed against such a deadly disease.

But the WHO only advises. It is up to individual countries whether they want to follow its recommendations.

Michael Osterholm, director of the University of Minnesota’s Center for Infectious Diseases Research and Policy, said the move by the Chinese is “a harbinger of things to come.”

Osterholm said that global health aid and assistance is a form of diplomacy. If the current U.S. administration is looking to cut back on what it spends to help developing countries with their health problems, it should expect to see China step in to gain more influence.

“This is the beginning of what I think is a very consequential change in international public health response, with impact on overall global health security,” Osterholm said. “By beginning to turn our back on global health security … we have not understood that those that provide the emergency response and those that provide the vaccines and those that provide the care and treatment are often those who also have access at the table of the highest levels of government for every other thing, including trade, resources and all aspects of regional security.”

The news may also cause concern among American and European companies that have long been working on Ebola vaccines and drugs and have struggled to find opportunities to test them during sporadic outbreaks. Janssen, the vaccines division of Johnson & Johnson, has been developing an Ebola vaccine for years and has also been interested in trying to test the product in this outbreak.

Little is known about the Chinese vaccine, which was licensed without a Phase 3 trial—meaning there is no human efficacy data to prove that it is protective. Its approval was based on animal studies and small trials that showed it was safe and induced antibody production in healthy people who received it.

The Merck vaccine was shown to be effective during the West African outbreak, but has still not made its way through the licensure process.

“What makes it difficult is that if the Chinese license a product and bring it to a low- or middle-income country … and we’re still trying to evaluate those vaccines and drugs that we believe are important, it may actually create a real challenge,” Osterholm said. “The country may well be motivated to use the licensed [Chinese] product, even without potentially the same rigor of evaluation that we’re putting our vaccines through.”

The Merck vaccine is being used in a ring vaccination approach, where contacts of cases, and contacts of the contacts, are offered vaccination in an effort to protect all those who may have been exposed. Health care workers, too, have been vaccinated. As of Wednesday, 1,826 people have been vaccinated with the Merck vaccine in the current outbreak.

The outbreak, which was declared a month ago, has slowed markedly, although the DRC health ministry reported a new confirmed case on Thursday, the first in about 10 days. The patient, who is in Iboko, was in contact with someone who earlier died of Ebola.

Daily case counts—a combination of confirmed, probable, and suspect cases—have fluctuated up and down over the past week or two. That’s because the government has been reporting suspect cases without waiting for confirmatory tests. It is not unusual to see seven suspect cases reported one day and discarded the next.

On Thursday, the government reported 62 cases, 10 of which are suspect cases.

The combination of confirmed and probable cases—people who died before testing began—provides a clearer picture of the trajectory of the outbreak. That number now stands at 52, with 27 deaths.

Republished with permission from STAT. This article originally appeared on June 8, 2018