Ebola vaccine trials could start in Africa in January

Trials of Ebola vaccines could begin as early as January in the West African countries most affected by the virus, a World Health Organization official said Tuesday.

The Centers for Disease Control and Prevention has estimated that Ebola could affect up to 1.4 million people by January if the outbreak is not controlled. According to the WHO, the outbreak has infected more than 9,200 people and killed more than 4,500, mostly in Sierra Leone, Guinea and Liberia.

Although there are no approved vaccines or treatments for Ebola, experts have said that vaccines are the best hope of getting the outbreak in West Africa under control and preventing it from spreading across the rest of the continent.

Scientists are racing to test the leading vaccine candidates. Others are in earlier stages of development.

The first human Ebola vaccine study began in September at the National Institutes of Health in Bethesda, Md., where the vaccine was developed. U.S. health officials say they expect to have preliminary data on safety and effectiveness by the end of this year. Human studies of this vaccine are also underway in the United Kingdom and the African nation of Mali, and it will be used in clinical trials in Switzerland by February, said Marie-Paule Kieny, WHO assistant director-general.

If the vaccine proves safe and effective in these early trials, the NIH vaccine could be shipped to West Africa early next year for "compassionate use," even if it's not yet approved, U.S. officials have said. The experimental vaccine could be made available to people at high risk for Ebola -- such as health workers -- just as companies have made the unapproved drugs ZMapp and TKM-Ebola available to infected patients.

GlaxoSmithKline has signed on to further develop the NIH vaccine and mass produce it. The company has said that it could produce up to 1 million doses by the end of 2015. The vaccine uses a safe version of a chimpanzee adenovirus, similar to a virus that causes respiratory illness in humans, to ferry genetic material into patients. Researchers hope the vaccine will stimulate patients' immune systems to produce antibodies against Ebola.

Canada also has developed an Ebola vaccine and began shipping 800 vials to the WHO's headquarters in Switzerland Monday. The shipment is expected to arrive Wednesday. That vaccine, which has been licensed to NewLink Genetics in Iowa, will be used for clinical trials in Switzerland, Germany and the African nations of Gabon and Kenya, Kieny said.

The Walter Reed Army Institute of Research in Maryland began human trials of the Canadian vaccine last week. That vaccine, known as a VSV vaccine, is made with a vesicular stomatitis virus, which belongs to the same family of viruses as rabies.

January would mark the first test of tens of thousands of doses of experimental vaccines in the hardest-hit nations in West Africa, Kieny said.

Scientists, ethicists and public health officials are still debating who should get the first experimental doses. Kieny said researchers may want to test the vaccine on people who are at high risk of Ebola, such as relatives of people already diagnosed with the virus.

It also would make sense to vaccinate health workers against Ebola because keeping them healthy allows to save more lives, said ​William Moss, a professor at the Johns Hopkins School of Public Health.

According to the WHO, 423 health workers have developed Ebola and 239 have died. In the USA, two nurses who treated the country's first Ebola patient have been diagnosed with the disease and are hospitalized for treatment.

Testing Ebola vaccines will cost hundreds of millions of dollars, Kieny said.

"The funding scenario has not been worked out," Kieny said. "The assumption is that funding will come from the countries helping with the response: the U.S., the United Kingdom, France, Norway, Germany," as well as from the Global Alliance for Vaccines and Immunization.