The story behind the Ebola virus vaccine

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Editor's note: World Immunization Week, celebrated in the last week of April, aims to promote the use of vaccines to protect people of all ages against disease, according to the World Health Organization. This year's theme is “Protected Together: Vaccines Work!” In this episode of “Come Together” series, we are taking a closer look at the scientists who had worked on Ebola virus vaccine for decades.

Looked through a microscope, the Ebola virus, one of the deadliest viruses in human history, can actually appear beautiful.

Though exquisite in composition, Ebola is a fatal virus, which has taken tens of thousands of lives globally.

The World Health Organization (WHO) has declared Ebola outbreaks an international public health emergency several times since its first outbreak in 1976.

Many people still remember the outbreak in 2014 that led to more than 10,000 deaths in West Africa. In efforts to curb a new outbreak, the WHO launched a vaccination campaign. In 2014 alone, the U.S., Canada, and China have launched clinical trials for Ebola vaccines.

Research team attempts to use Chinese developed Ebola vaccine to help with control and prevention of the disease. /VCG Photo

How can we beat the virus? The answer may well lie in the virus itself.

As a member of the Chinese research team working on the Ebola virus vaccine, Dr. Chen Wei, professor from Academy of Military Medical Sciences, believes that the Ebola is just like a padlock, with the unlock code constantly changing.

“Normally, vaccines can simply be made by reducing or killing the virulence of the virus. But the Ebola vaccine could not be made in this way, because it will not meet our needs,” Dr. Chen noted.

Few people could foresee the significance of her work back in 2004 when Dr. Chen select the Ebola virus as her research area. “Making a vaccine to cure this deadly virus is like a mountain peak for vaccine scientists around the world to conquer. That's my dream, too,” Dr. Chen recalled.

After years of work, Dr. Chen and her team members found that viral vector vaccines may be a solution.

“We put glycoprotein genes that express the Ebola virus into the vaccine, so that it contains a ‘password,'” Dr. Zhu Tao, research fellow on Ebola virus vaccine and Dr. Chen's coworker, told CGTN. “When the ‘password' reaches the human body by vaccination, it will express Ebola virus glycoprotein, therefore establishing immunogenicity.”

On October 19, 2017, China approved the new drug application of a recombinant Ebola virus vaccine.

What is the difference between the vaccine developed by Dr. Chen's team and its counterparts in the West? “All these vaccines are called vector vaccines. But our vaccine is based on the 2014 Ebola virus strain, while those developed by Canada and the U.S. are based on the 1976 strain,” Dr. Zhu said.

“Also, our vaccine comes in the form of freeze-dried powder, which could be stored at 2-8 degrees Celsius for a longer time,” he added.

Clinical trials conducted by Chinese scientists have proved the safety as well as the high immunogenicity of the new vaccine. In fact, some of the staff from the National Disease Control Center and the UN peacekeeping force have already received the vaccination before heading to Africa.

Medical team sets out for the Republic of Sierra Leone to help them fight against the Ebola virus. /VCG Photo

The trial has also been widely acknowledged throughout the world. “China was one of the first countries that actually acted and sent supplies directly to our country,” said Yvette Stevens, permanent representative of Sierra Leone to the UN in Geneva.

“Medical supply; technical assistance. You name it,” echoed Paul Wolokollie Tate, representative of Liberia to the UN in Geneva.

So far, no Ebola case has ever been spotted in China. After years of research, Chinese scientists' hard work may be paying off. So how can China's fight against Ebola shed light on epidemic control in the future?

“With the success of Ebola virus vaccine, we would be able to tackle more types of viruses such as Zika and H7N9 and bring them under control,” said Dr. Chen. “Citizens need no longer fear epidemics as they once did when SARS hit the world in 2003.”

“I really hope that there will be no more orphans in Africa due to the Ebola virus,” Dr. Chen added.