Why the Ebola vaccine’s ups and downs?

As people’s moods fluctuate as the new crown vaccine progresses and frustrates, let’s look at the history of another more potent infectious disease Ebola vaccine. Infectious diseases know no borders, but the research and development of infectious disease vaccines vary greatly depending on the time of the outbreak, the scope of impact and the number of deaths.
Author | Li Yiying

Editor-in-Chief | Zhu Liyuan

Source: Duan Duan Sauce

The emergence and disappearance of infectious diseases are never shifted by people’s will. On June 1, 2020, the Director General of the World Health Organization (WHO) Tan Desai said at an online press conference in Geneva that the Government of the Democratic Republic of the Congo announced on the same day that a new project appeared near the city of Mbandaka in the northwestern province of Equatoria Of the Ebola virus outbreak. The preliminary information provided by the country’s Ministry of Health is that as of that day, six cases of Ebola were found, of which four have died. Tan Desai said that this reminds people that 2019 coronavirus disease is not the only health threat. Although most of the attention is focused on the new coronavirus pandemic, WHO continues to monitor and respond to many other health Emergency situations. The closest Ebola outbreak to us began at the end of 2013, which was the largest and most complex outbreak since the virus was first discovered in 1976. The outbreak first occurred in a small village in Guinea. An 18-month-old boy developed a sudden illness, and died of fever, black stools, and vomiting two days later. However, it was not confirmed as Ebola until March 2014, and the outbreak spread to Sierra Leone and Liberia through the land border. Ebola virus is a rare but often deadly virulent infectious disease virus. The incubation period of the virus is as long as 21 days. It is transmitted to humans through wild animals and spreads among people. The average mortality rate is about 50%. Symptoms after being infected with Ebola virus are complicated, including high fever, accompanied by fatigue, headache, myalgia, sore throat, etc., and nausea, vomiting, abdominal pain, diarrhea, rash, etc., and high fever will continue after the third day of onset. Poisoning symptoms, varying degrees of bleeding, and even unconsciousness, shock, and multiple organ failure.

For more than 40 years since its discovery, Ebola has always been a global health challenge. The 2013-2016 West Africa Ebola outbreak caused more than 11,300 deaths. Like the new coronavirus, because there are no special drugs, vaccination is the only way to protect everyone.

The birth of the Ebola vaccine seems to be a perfect case of joint collaboration between all walks of life during the outbreak of infectious diseases.

The widely-acclaimed story is: In 2014, the Ebola outbreak broke out again in West Africa, and the world’s top scientists began to discuss the response to this severe infectious disease again. One of them was Canadian scientist Gary Kobinger. ). The results of the Ebola vaccine he and his team devote themselves to have won the recognition of the Canadian Health Department and the World Health Organization, and have been jointly conducted clinical trials by multiple institutions.

The epidemic has made clinical trials exceptionally smooth: from 2014 to 2016, at the end of the Ebola outbreak in the three West African countries, the vaccine began a large-scale clinical trial in Guinea, and the results proved that the immunization effect is significant, with only one dose of more than 5,000 vaccines. There were no subsequent cases of infection.

In December 2016, scientists from multiple institutions jointly published an article in The Lance (Thelancet), announcing the results of this vaccine test: 100% effective. In November 2019, the European Union announced that this Ebola vaccine was approved for marketing and became the world’s first officially approved Ebola vaccine. Just one month later than the European Union, the US FDA approved this live attenuated vaccine called Ervebo to be marketed in the United States.

Not only that, the vaccine also created the fastest prequalification record for WHO vaccines in history, and became “a major success in global public health.”

But the fact behind this is that the Ebola virus has been discovered for more than 40 years, and scientists have made major breakthroughs in the virus itself and vaccine development many years ago. Everything is due to the Ebola case, and it is concentrated in several countries in Africa, such as the Congo, Gabon, and Sudan, which have very poor medical conditions. No public or commercial institutions are willing to invest in support, which has delayed the availability of vaccines for decades. as long as.

In response to this phenomenon, there has been a rather harsh and discriminatory statement in the academic community: “There are still fifty white patients away from the introduction of Ebola treatment/vaccines.” This sounds quite unfair to the people of Africa, but looking back on the history of the development of this vaccine, it is true.

1 From Germany to Canada, a key vaccine carrier was discovered

The discovery of Ebola virus can be traced back to the 1960s and 1970s.

In the autumn of 1967, several laboratory workers in Marburg and Frankfurt, Germany, and Belgrade, the former Yugoslavia, simultaneously broke out a severe hemorrhagic fever disease, with 31 cases of illness and 7 deaths. The results of the epidemic virus investigation found that the source of the outbreak was a virus-carrying monkey imported from Uganda in Africa in the laboratory to develop a polio vaccine. Later, the hemorrhagic fever disease was named Marburg virus (Marburg Virus).

Nine years later, in 1976, Ebola virus, a brother of the same family of filamentous viruses, was first discovered in the Ebola River region of southern Sudan and the DRC. Although very rare, both viruses can cause highly pathogenic new infectious diseases with severe consequences. At that time, the scientific community had not officially started to study Marburg virus or Ebola virus.

In the early 1980s, Hans-DieterKlenk, a scholar who had just arrived in Marburg, noticed this new virus and suggested that his student Heinz Feldmann (HeinzFeldmann), You can try to change the research direction from common viruses such as influenza to such powerful viruses. The two hit it off together, laying an important foundation for Feldman’s research on Ebola virus afterwards.

In 1990, a scientist at Yale University, John (Jack) Rose, tried to use recombinant Vesicularstomatitisvirus (VSV) as a carrier platform for vaccines. Although Vesicular Stomatitis Virus (VSV) can cause oral disease in cattle, it rarely infects people, does not make people feel uncomfortable, and induces surprisingly high levels of antibodies.

Ross envisages that if this virus can be used as a vaccine carrier for influenza, HIV and other viruses, teaching the human body to identify harmful viruses without harming people, a huge breakthrough will be made in the development of new vaccines.

The subsequent development also proved Rose’s genius vision.

Some people describe this vaccine-making technology as “sheep in sheep’s clothing”, which means that the protein on the surface of the virus to be prevented is loaded on the surface of the virus without any power, and no additional adjuvant can be used to induce the vector to produce. The body’s immune response. Now, people already know that using viral vectors to develop vaccines is feasible, including the successful dengue vaccine, but at the time this was an extremely innovative idea.

In the following six years, after repeated failures, Ross and his team finally succeeded in influenza virus using VSV as a carrier. The influenza virus vaccine based on them gave mice a single dose of immune protection. “The antibody expression is excellent!” Ross sighed. Soon, VSV was used as a vaccine carrier for a series of viruses, including bird flu, measles, SARS, MERS, etc., with success.

Based on this, Ross believes that, theoretically, it is equally effective against the Ebola virus.

But the experiment has never been started-as the highest level of biohazard virus, it cannot be studied without a matching high-security laboratory, so Ebola-related recombinant virus vaccine research has been shelved.

Soon, this carrier patent was granted to Wyeth and shared with more than one hundred laboratories worldwide. With this innovative carrier, scientists have the opportunity to build a single Ebola virus gene on VSV, which is not only convenient, fast and cost-effective, but also greatly facilitates the research work.

By 1999, the safety of biological laboratories continued to escalate, and the National Microbiology Laboratory in Winnipeg, Canada on the other side of the ocean began preparations, including a Level 4 laboratory for biosecurity needed to study Ebola virus. The aforementioned Feldman of the Marburg University Virus Research Institute was also hired from Germany to lead his special pathogen research team-he was a member of the research group that studied VSV vectors in Germany that year, and was the first to start research in Egypt. One of the scientists of the Bora virus.

2 The success of animal experiments

When Feldman left Germany for Canada, he was allowed to take some virus samples, laying the foundation for his future research.

In the most advanced laboratory in Winnipeg, Feldman and his team finally had the opportunity to really test whether the VSV vector is useful for Ebola virus. They found that mice that were not injected with Ebola virus VSV antibody were All of them died in the face of Ebola virus, and the mice injected with antibody were safe and sound.

Whether it is the development of drugs or vaccines, animals that exhibit symptoms and characteristics similar to human diseases are the first choice in animal experiments. Mice or monkeys are the most common test species, especially non-human primates. Their physiological models and tissues The traits such as structure and immune response are very similar to humans.

After the mouse experiment was successful, Feldman and they should have entered a higher-level animal experiment when a new threat came.

In 2003, a brand new severe respiratory syndrome, later known as SARS infectious disease, appeared in some countries in Asia and spread outward. Scientists from the Canadian Microbiology Laboratory immediately joined in for research.

But Thomas W. Geisbert, an American scientist who collaborated with Feldman, did not stop and continued to look for more evidence from primates. He is an Ebola virus expert and one of the developers of the Ebola vaccine at the University of Texas Galveston Medical Branch.

Later, Canada and the United States collaborated to prove that the VSV vector Ebola vaccine was completely protected in cynomolgus monkeys, and the vaccine induced significant humoral and cellular immune responses.

In June 2005, the results of this study were published in the top journal “Nature-Medicine” (naturemedicine), the research results for the first time in non-human primates to verify the feasibility of Ebola virus vaccine based on VSV vector, And it only needs to be immunized once to get fast and complete protection, which has very good practical value.

It is worth mentioning that the study also verified the preventive effect of the vaccine after virus exposure. Feldman et al. found that vaccinating Ebola virus vaccines based on VSV vectors for 24 hours after guinea pigs and mice were challenged can achieve 50% and 100% protection, far exceeding adenovirus vector vaccines for 30-60 minutes. During the protection period, 50% protection was achieved even within 20-30 minutes after exposure of rhesus monkeys to Zaire-type Ebola virus, and within 20-30 minutes after being challenged by Sudan-type Ebola virus Can achieve 100% protection.

With respect to this research, the scientists have finally been able to confirm that the model of using VSV to load viruses is not only safe, but also effective as a basis for the development of multiple vaccines.

“The door to the Ebola vaccine has really been opened.” Gasbert and the entire team were very excited about it, and announced to the media at the time that this Ebola vaccine named rVSV-ZEBOV may be in both Conduct human clinical trials within the year, and wait until 2010 or 2011 to complete all procedures for listing.

3 Cold clinical development

Scientifically, this discovery is extremely exciting. But in reality, this is not even the beginning.

Soon, Gasbert found himself too optimistic.

“Our research results are too exciting, but what can we do?” When asked about their breakthrough research results, Feldman reluctantly replied to the media, “but just went to the bar next door to drink Glass of wine before going back to work.”

“No one wants to invest in the development of this vaccine,” he added.

In Canada, special pathogen research projects have been placed in the most obscure corners by the government. As soon as the budget season arrives each year, this type of research is always a budget-conscious project by the government. During the ten years from 2004 to 2014, every budget season, Frank Plummer, then the scientific director of the Winnipeg Microbiology Laboratory in Canada, had to respond to the government’s question again and again, why Canada needs to study Ebola. Viruses that do not exist in our country.

Industry insiders admit that failure to carry out follow-up research on this promising drug candidate reflects a greater failure: people in poor countries suffer from certain diseases, but drugs or vaccines against these diseases cannot Was produced.

Unlike new medicines for treating diseases, vaccines are special medicines for healthy people to prevent diseases. The evaluation of their safety and effectiveness will always run through all stages of pre-clinical research, clinical trials, and post-market evaluation.

Regardless of the technical route used, a vaccine usually takes 5 to 20 years from R&D to marketing, such as influenza vaccine (14 years), smallpox vaccine (26 years), polio vaccine (20 years), dengue vaccine (20 Years), most vaccines have been in development for more than 10 years and cost more than 1 billion US dollars.

What Canada’s Wimbledon Laboratory has done is only the important first half of vaccine development—using different animals to verify the long-term toxicity, allergic reaction, reproductive toxicity and other safety evaluation indicators of the vaccine, also known as “preclinical research”. However, the largest and most critical step for a new vaccine from R&D to marketing is the human clinical trials and the new drug listing process, which generally needs to be completed by pharmaceutical companies.

For the pharmaceutical industry, this is “a business destined to lose money.” In the 2010s, the Ebola virus was discovered almost thirty years ago, but the deaths caused by it were only thousands of people, and concentrated in several small countries in Africa. Not to mention that any new drugs and vaccines require huge amounts of investment. Even if a large amount of investment is made, these countries affected by the virus may not be able to afford vaccines or drugs at all. Enterprises that need to manufacture this vaccine are free of charge through certain public welfare projects. Donate. Therefore, it is difficult for large pharmaceutical companies to have the willingness to develop such a rare infectious disease that occurs only in poor areas.

In 2015, an Ebola virus research paper by the Chinese Center for Disease Control and Prevention Yang Limin and others also pointed out that vaccination is a routine method of prevention and control of infectious diseases, but currently the Ebola virus vaccine is not on the market because of the disease. Rare and limited by region, R&D vaccines lack economic value and cannot attract the attention of vaccine R&D companies.

4 A laboratory accident

An accident at a German laboratory unexpectedly became an excellent case for human trials and emergency use of the Ebola vaccine.

On March 12, 2009, a German researcher stabbed her finger when exposed to Ebola virus in the P4 laboratory. Although there was no bleeding at the time, her skin was punctured while wearing three layers of gloves. She was urgently taken to the University of Hamburg Medical Center and contacted researchers in Canada and the United States to see if there were any rescue measures.

After several rounds of risk assessments, the researchers cited nine key points and believed that the Ebola vaccine (rVSV-ZEBOV) developed by Canadian and American scientists should be vaccinated immediately, and she agreed. Some previous animal experiments have shown that antibodies can still be produced within 48 hours of exposure to the virus, but the vaccine has never been vaccinated in humans before this laboratory worker.

Because of the risk of lethal viruses, the Canadian government agreed to provide this laboratory vaccine. Packages containing the vaccine were sent from Canada after the first conference call and arrived in Hamburg on the morning of March 14. 48 hours after the accident, the researcher was vaccinated in this compartment. She herself became a subject closely followed by researchers.

On March 15, the researcher developed fever and muscle pain, and the medical staff did not treat her. They wanted to confirm whether it was due to the onset of symptoms of Ebola infection or a routine adverse reaction after vaccination. Her fever fell that night, and within 21 days after being closely monitored, she did not have any symptoms of Ebola infection and was eventually discharged safely.

Until today, researchers have not been able to confirm whether the researcher was not infected with the Ebola virus, or had an infected but rescued vaccine that was used urgently, although most people tend to believe she is not infected.

But this emergency use across borders laid the foundation for Ebola’s human trials and proved that the vaccine had no obvious side effects in humans.

Until 2014, the VSV Ebola vaccine developed by scientists from the United States and Canada did not leave the laboratory. For all researchers who have worked hard for this vaccine, this is still just a shelved scientific idea.

In the meantime, in order to recommend this research to be finally marketed, Winnipeg Laboratories applied for a patent for this model and authorized this carrier to Wyeth. After that, they began to seek cooperation with pharmaceutical companies on a large scale, hoping to push the vaccine into the clinical development stage.

After talking about countless companies, large and small, only one small company called BioProtectionSystemsCorp. (a subsidiary of NewLinkGenetics) was interested in buying the patent right at a low price of $200,000, claiming to promote the vaccine into the clinic. development stage. But for BioProtection, this is just a business decision to increase their asset portfolio. BioProtection was later acquired by LumosPharma, and they never promoted clinical development of the Ebola vaccine.

“The market demand for Ebola vaccines has not been great. If they are produced in large quantities, who are they going to sell to?” Professor Gasbert, one of the developers of Ebola vaccines, understood that “sometimes only bigger crises come. To trigger discussion.”

A few years later, Gasbert said.

5 New outbreaks are coming

As mentioned at the beginning, the latest Ebola outbreak occurred at the end of 2013. At first, people thought it was just cholera. Until January 2014, several immediate relatives of the dead boy also had similar diseases and died with it. Many medical staff were also infected and killed.

In the Democratic Republic of the Congo, a severely ill with Ebola infection is in an innovative local isolation shed. Finbarr O’Reilly 丨The New York Times

According to WHO’s review, several factors have led to the underestimation of the epidemic. Although cases have been imported into Liberia and Sierra Leone from Guinea, no one realizes that it is Ebola virus, and no one has officially reported it to WHO. The outbreaks in these two countries first occurred quietly for several weeks until the chain of transmission When the number of viruses increased into the capital and capital cities, and it was difficult to track down because of the large number of infections, it finally attracted people’s attention.

On March 21, 2014, the WHO Collaborating Center and the Pasteur Institute in Lyon, France confirmed that the pathogen was a filamentous virus and narrowed the diagnosis to Ebola virus disease or Marburg haemorrhagic fever.

The next day, the laboratory confirmed that the pathogen was the Zairian genus, the deadliest virus in the Ebola family. On the same day, the Government of Guinea issued a warning to WHO on the epidemic of Ebola virus disease. The description of the epidemic at that time was “rapid development”.

On March 23, the WHO website announced the outbreak. At that time, the official report had 49 confirmed cases and 29 deaths. Before the end of the week, the outbreak has spread from the countryside to the city, and confirmed cases have appeared in the capital of Guinea.

Another key figure, Gary Kobinger, appeared. He not only developed an Ebola therapeutic drug ZMapp, but also pushed the Ebola vaccine into clinical trials and eventually succeeded.

As the head of the Special Pathogens Department at the National Microbiology Laboratory in Winnipeg, Canada, he immediately contacted the WHO when he heard the news, hoping to put the rVSV-ZEBOV vaccine previously developed by the laboratory into use to help contain the epidemic in West Africa.

WHO’s first response was to refuse, citing the fact that laboratory drugs are too immature to be used in humans at this time. Later, another Ebola candidate vaccine (cAd3-ZEBOV) developed by the National Institutes of Health (NIH) and entered clinical stage was also rejected by WHO. “No one expressed interest in this vaccine. “.

But Gary Kubinger did not want to give up on this, he tried to find supporters.

At the time, in addition to international aid agencies such as WHO, the US Centers for Disease Control and Prevention, and the European Commission, MSF had also been closely monitoring the outbreak and continued to emphasize with WHO and other agencies that local The situation is rapidly deteriorating and urgent measures are needed.

Gary Kubinger found Dr. Armand Sprecher of MSF and persuaded him to promote vaccine clinical trials together.

In August 2014, the number of cases continued unabated, and WHO declared the epidemic a global health emergency. A few days later, the Canadian government announced its willingness to donate the laboratory’s rVSV-ZEBOV vaccine.

In the meantime, there were episodes against the use of the vaccine: some people said that it is unethical to provide Ebola patients in West Africa with drugs that have never been used, and at the same time, because of the weak medical conditions in West Africa, clinical trials Security cannot be guaranteed. Some people also cited the 1996 meningitis drug incident that killed 11 children and caused a large number of children to be deaf to support this view.

The scale of the epidemic continues to expand, and WHO has to convene an emergency meeting. In view of the huge threat and adverse effects of the Ebola virus, the expert group finally concluded that trying to use experimental vaccines and therapies is a “moral imperative.” But the premise is to carry out a clinical trial of safety assessment and determine the applicable dose.

The scale of the joint team is very strong. From the WHO website, we can see that the rVSV-ZEBOV trial was funded by WHO and supported by the following: Wellcome Trust, UK Department for International Development, Norwegian Ministry of Foreign Affairs, Norwegian Public The Institute of Health (supported by the Norwegian Research Council), the Government of Canada (supported by the Public Health Agency of Canada, the Canadian Institutes of Health, the International Development Research Center, and the Department of Foreign Affairs, Trade and Development) and MSF.

After that, the three countries with the most severe outbreaks—Guinea, Liberia, and Sierra Leone—all expressed willingness to conduct human clinical trials of the Ebola vaccine within their own country.

Gary Kubinger’s team also started to travel to and from West Africa to help build the infrastructure for clinical trials.

A key issue arises. NewLink, the owner of the rVSV-ZEBOV vaccine, has never conducted a clinical trial before.

When WHO announced that it was going to conduct clinical trials in Africa, they were completely dumbfounded. Obviously, NewLink does not have the corresponding professionalism and ability to undertake this work. The World Health Organization and other agencies, including the US government, need to find a more experienced pharmaceutical company as a partner.

There are not many potential candidates.

According to reports, among the large pharmaceutical companies with relevant vaccine development experience, Sanofi has no intention of cooperation. Novartis also sold the vaccine department to GlaxoSmithKline earlier that year, and GlaxoSmithKline is stepping up its own research and development. Although Ebola vaccine, Johnson & Johnson’s vaccine department is also developing Ebola vaccine, but progress is too slow. In the end, the expert team selected Merck & Co. (known as Merck in North America), which has similar vaccine production experience and corresponding professionalism as VSV vaccine, and also understands how to mass-produce mass production and manage the entire process of mass-production. .

“We know how to produce vaccines on a large scale, understand the technology required to produce this vaccine, and have the ability to complete it,” said Julie Gerberding, chief patient officer of Merck.

6 Building a crowd immune barrier

On September 30, 2014, Dallas, Texas, USA imported the first Ebola case from West Africa by air.

Ebola walked out of Africa to North America. Everyone realized the urgency of the incident, and the negotiation progressed rapidly thereafter. On November 24, 2014, Merck and NewLink reached an agreement to pay NewLink US$50 million for research, development, preparation and distribution of vaccines.

At the same time, two Ebola vaccine candidates developed by NIH in the United States and Health Canada have begun human trials in West Africa.

When the researchers conducting clinical phase I and phase II trials proceeded with data analysis, another group of researchers began preparing for a critical phase III clinical trial. The phase I and II trials are to determine whether the vaccine is safe, and the phase III clinical trial will test whether it is really effective in humans on a large scale.

In March, July 2015, the rVSV-ZEBOV vaccine started a phase III clinical trial in Guinea. However, with the decline of the epidemic, the number of cases continued to decrease, which put a severe test on the design of the trial protocol.

The R&D team creatively adopted a clinical trial design, the so-called “circumferential vaccination” method-the same method was used to eliminate smallpox.

That is, when a new Ebola case is diagnosed, the research team tracks everyone who may have been in contact with the case in the past 3 weeks, including those who lived together, visited by the patient, or contacted with the patient, their clothing or Underwear have close contact with people, as well as certain “contact contacts”, a total of 117 groups (or “rings”) are identified, with an average of 80 people in each group.

In the beginning, the researchers immediately or randomly vaccinated each “ring” after 3 weeks and provided the vaccine only to adults over 18 years of age. Immediately after the release of the interim results showing the effectiveness of the vaccine, the vaccine will be provided to all “ring” people, and the trial is also open to children over 6 years old.

As the trial progressed, relevant data indicated that the vaccine was beginning to work, and communities that had experienced persistent transmission no longer had cases. In a randomized vaccination study conducted in Guinea from 2014 to 2016, 3537 laboratory-confirmed contacts of Ebola patients, as well as contacts of contacts received “immediate” or “21-day delay” Vaccination.

By comparing the cases of the 2108 immediate vaccination group and the 1429 delayed vaccination group, the researchers determined that the vaccine was 100% effective in patients who had symptoms for less than 10 days. In the “immediate” group, no onset of Ebola infection was observed, while in the “21 day delay” group, only 10 cases were observed.

Dr. Marie-Paule Kieny, the leader of the WHO Ebola drug development group responsible for the trial, publicly stated: “This result proves that the vaccine is 100% resistant to the threat of Ebola virus.”

He further explained: “If the Ebola virus makes a comeback in the future, because of this vaccine, we are ready to respond.” According to his laboratory, if there is a new Ebola outbreak, pass the timely vaccine Vaccination, non-infected people have nearly 90% immunization rate.

The WHO data and safety monitoring committee also formally concluded that the vaccine is working, and recommended that medical personnel vaccinate people who have been exposed to Ebola virus infection as soon as possible.

In addition to showing high efficacy among those who are vaccinated, the trial also showed that the surrounding vaccination method (the so-called “crowd immune barrier”) can also indirectly protect the unvaccinated people in the ring from Ebola. Viral infection.

In less than a year, the researchers completed a full-phase trial from the first human dose study to the third-phase efficacy study-under normal circumstances, this time is as long as 6 to 8 years. Feinberg, the CEO of the International AIDS Vaccine Advocacy Group, lamented that there has never been such a successful trial so quickly.

On July 31, 2015, the relevant test results were published in The Lancet. The editor of the magazine wrote that this experiment not only proved the superb skills of the research team, but also proved that society can bring hope to countries destroyed by the epidemic. “Prior to this, Guinea has never had such a scale. Clinical trials.”

In December 2016, the final results of the clinical trial of the Ebola vaccine were published in The Lancet, showing that this vaccine is highly protective against lethal viruses.

In the spring of 2018, when the Ebola virus broke out in the Equateur Province of the Democratic Republic of Congo, WHO vaccinated the Ebola vaccine donated by Merck East in the form of “sympathetic medicine”. Since then, there have been more than 260,000 people Vaccinated, including more than 60,000 health workers and front-line workers in the Democratic Republic of Congo and Uganda, South Sudan, Rwanda and Burundi.

At the end of 2019, the vaccine passed the drug approval procedures of the European Union and the US FDA, and was finally marketed.

“Although these convincing results are too late for those who lost their lives during the Ebola outbreak in West Africa, when the next Ebola outbreak attacks, we will no longer have no defense.” WHO Ebola drugs Dr. Kenny, the leader of the R&D team, said.

In March 2020, when the whole world was fighting the new crown epidemic, Congo (DRC) announced the discharge of Masiko, the last case of Ebola virus infection in the country (and at the time).

However, a month later, the event to celebrate the end of the Ebola epidemic has not yet begun. On April 10, the city of Beni confirmed a new Ebola case, which then became 6 cases, of which 4 people have died. On June 1, Congo (DRC) announced a new round of Ebola outbreak, which was the 11th Ebola outbreak in Congo (DRC) since 1976.

“Vaccines are the best way to eliminate the epidemic and an important way to prevent the outbreak in the future.” Marie-PauleKieny emphasized that for the world, the enlightenment from the Ebola outbreak is that more attention needs to be paid to the current main impact on the poor and poverty. The disease of the country, because when the pandemic began, no country or region could be left out.

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