Bill Gates recently published an article on his blog that raised the global need to reopen the COVID-19 vaccine.
"Practically speaking, if we want to return to normal, we need to develop a safe and effective vaccine." Gates said in a blog: "We need to manufacture billions of vaccines, we need to spread them to every one of the world Corner, all these things need to happen as soon as possible. "
Gates said that he is optimistic that a safe and effective vaccine may appear within 18 months, although the shortest may only take 9 months, the longest or up to two years.
The following is the original Gates:
One of the questions I have been asked the most these days is when will the world return to the state before the coronavirus pandemic last December. My answer is always the same: when we have an almost perfect medicine to treat the COVID-19 virus, or when almost everyone on the earth is vaccinated with the COVID-19 virus.
The former case is unlikely to happen in the near future. We need a miraculous treatment drug that should have at least 95% effectiveness to stop the outbreak. However, most current drug candidates are not as powerful. These drugs can indeed save many people's lives, but not enough to get us back to normal.
Then we only have the option of vaccine.
Humans have never faced a more urgent task than the development of the COVID-19 virus vaccine. In fact, for human society to return to normal, a safe and effective vaccine must be developed. We need to make billions of doses of vaccine and send it to every corner of the world-all of which needs to happen as soon as possible.
This is indeed a daunting job. Although our foundation is the largest vaccine supplier in the world, this vaccine development work has dwarfed everything we have done before. This work requires unprecedented global cooperation. This work must be successful because we have no choice.
About this competition for the development of the COVID-19 virus vaccine, here is what you need to know.
The whole world is developing this vaccine at the fastest speed in history.
Dr. Anthony Forsi said that he believes that the development of the COVID-19 virus vaccine will take about 18 months. I agree with him, but the exact time is difficult to determine, it may only take 9 months, or it may be as long as 2 years.
Although 18 months sounds like a long period of time, this is the fastest speed scientists can develop vaccines. Vaccine development usually takes about 5 years. Once a disease is targeted, the corresponding vaccine must be manufactured and tested on animals. Only then can we begin to test its safety and effectiveness in humans.
Safety and effectiveness are the two most important indicators to measure a vaccine. Safety refers to whether the vaccine is safe when administered to humans. Some minor side effects (such as mild fever or pain at the injection site) are acceptable, but people should not get sick due to vaccination.
Efficacy measures how well the vaccine protects you from a certain disease. Although ideally you want a vaccine to be 100% effective, in fact not everyone can get immunized after vaccination. For example, this year's flu vaccine is only 45% effective.
In order to test the safety and effectiveness, each vaccine needs to go through three stages of testing:
• The first stage is a safety test. For a candidate vaccine, you first need to test different doses on a small group of healthy volunteers to find the lowest effective dose that produces the strongest immune response. At this dose, there are generally no serious side effects.
• Once the dosage formula is determined, it enters the second stage. This stage tests the effect of the vaccine on those who need it. At this stage, hundreds of people were vaccinated. This vaccination group should include people of different ages and health conditions.
• Then, in the third stage, tens of thousands of people are tested for vaccines. This is usually the longest time-consuming stage because it occurs under the so-called "natural disease conditions". Give the vaccine to a large group of people who may already be at risk of infection, and then wait to see how many people the vaccine can save from getting sick.
After passing all three stages of testing, it is necessary to build a corresponding factory to produce the vaccine, and then submit the vaccine to WHO and various government agencies for approval.
For most vaccines, the development process described above is very effective. However, this normal development schedule is too long for the emergency situation we are currently facing. Each day of shortening the development process will have a huge positive impact on the world in terms of saving lives and reducing trillions of dollars in economic losses.
Therefore, to speed up this process, vaccine developers are doing everything possible to shorten the development time. The following diagram shows how researchers plan to shorten development time:
In the traditional R & D process, the R & D steps in the above figure are carried out in order to solve some key problems and unknown problems. This helps reduce financial risks because the cost of developing new vaccines is very high. Many candidate vaccines will eventually be eliminated, so in general, it is only after confirming that the previous step is successful before proceeding to the next step.
But for the COVID-19 virus, R & D funding is no longer a problem. The government and other organizations (including our foundation and an alliance called the Epidemiology Prevention Innovation Alliance (CEPI)) have made it clear that they will fully support vaccine research and development regardless of the cost. Therefore, scientists can perform several R & D steps simultaneously to save time. For example, the private sector, government, and our foundation will begin to identify production facilities that can produce a variety of potential vaccines. It doesn't matter if some facilities prove that they can't come in handy. In order to make progress in vaccine production, this is only a small price.
Fortunately, compressing vaccine development time is not the only way to speed up vaccine development. Another way is to test many different vaccines at the same time.
Currently, dozens of candidate vaccines are being tested on the R & D pipeline.
As of April 9, 115 different candidate vaccines for the COVID-19 virus are in development and testing. I think eight to ten of them look particularly promising. (At the same time, our foundation will also pay attention to all other candidate vaccines so as not to miss some of them that have potential.)
The most promising candidate vaccines have adopted various ways to protect the body from the COVID-19 virus. To understand these pathways, you need to understand how the human immune system works.
When disease pathogens enter your body, your immune system will produce antibodies. These antibodies attach to substances called antigens on the surface of pathogenic microorganisms and send an attack signal to your body. Your immune system keeps track of every pathogenic microorganism it has defeated, so that it can quickly identify and destroy invaders before they make you sick.
Vaccines circumvent the whole process by teaching your body how to defeat pathogens without getting sick. The two most common and probably the most familiar types of vaccines are inactivated vaccines and live vaccines. Inactivated vaccines contain pathogens that have been inactivated. Live vaccines are made from weakened live pathogens. Live vaccines are usually more efficient, but they are more likely to cause side effects than inactivated vaccines.
Inactivated vaccines and live vaccines are relatively "traditional" methods. At present, there are many candidates for these two types of vaccines against the COVID-19 virus. There are good reasons for using these two types of vaccines: the relevant development methods are very mature, and we know how to test and manufacture them.
But the disadvantage of these methods is that they are very time-consuming. Each dose of vaccine contains a lot of substances. Most of these substances are biologically active, which means you must cultivate them. Unfortunately, this process takes time.
This is why I am particularly excited about two new vaccine development methods (ie, RNA and DNA vaccine development methods). If either of the two methods proves effective, we are likely to be able to distribute the vaccine to the world faster. (For the sake of simplicity, I will only explain the development of RNA vaccines below. DNA vaccines are similar, except for genetic material and administration methods.)
Our foundation, through our own funds and CEPI funds, has supported the development of RNA vaccine development platforms in the past decade. We originally planned to use it to make an RNA vaccine to treat diseases like malaria that have a big impact on the poor. But now it seems that it is one of the most promising COVID-19 virus vaccine development options. The first candidate RNA vaccine to start human trials is an RNA vaccine produced by a company called Moderna.
The working principle of the RNA vaccine is as follows: Compared with the traditional method of injecting pathogen antigen into the human body, the RNA vaccine provides the human body with the genetic code required for antigen production. When antigens appear outside of your cells, your immune system will attack them and learn how to defeat future invaders in the process. This is actually turning your own body into a vaccine production plant.
Because RNA vaccines use your body to do most of the work, they do not require much material. This makes them faster to manufacture. However, there is still a problem: we are still not sure whether RNA is a viable vaccine platform. Since the COVID-19 virus will be the first combat target of RNA vaccines, we must prove that the platform itself is effective and that it can generate immunity. It's a bit like building your computer hardware system and your first software at the same time.
Although RNA vaccines show promise, we must continue to seek other options because we still do not know what the final COVID-19 virus vaccine will be. Therefore, before obtaining the final vaccine, we must move forward at full speed on as much research and development as possible.
The vaccine we finally obtained may not be perfect, but it is acceptable.
Smallpox vaccine is the only vaccine that can wipe out smallpox disease from the whole planet, but this method is also cruel. It left scars on everyone's arm. One in three people has side effects that are severe enough to prevent them from going to school or work and having to stay at home. There are even a few people who have more serious reactions.
Smallpox vaccine is not perfect, but it has completed its mission. The COVID-19 virus vaccine may be a similar situation.
A perfect vaccine should be completely safe and 100% effective. A single dose is enough to provide you with lifelong protection. It should also be easy to store and transport. I hope that the COVID-19 virus vaccine has all these characteristics, but considering our tight research schedule, it is likely that it will not have all these characteristics at the same time.
As I mentioned earlier, the two priorities are safety and effectiveness. Since we may not have the time to conduct long-term studies for many years, we will have to conduct strong first-phase safety trials and ensure that we have good real-world data to prove that the vaccine is completely safe.
In terms of vaccine effectiveness, we have more room for maneuver. I think a vaccine that is> 70% effective is enough to stop the outbreak. A 60% effective vaccine can also be used, but in this case, we may still see some local outbreaks. Any vaccine that is less than 60% effective is unlikely to generate sufficient group immunity to prevent the virus from spreading.
The biggest challenge will be to ensure that the vaccine is effective in the elderly. The older you are, the less effective the vaccine will be. Older people's immune systems are as old as other parts of their bodies, and they are slower to identify and attack intruders. For the COVID-19 virus vaccine, this is a big problem, because the elderly are the most sensitive and vulnerable to the COVID-19 virus. We need to ensure that they are effectively protected.
The herpes zoster vaccine for the elderly responds to this situation by increasing the strength of the vaccine. We may also take similar measures for the COVID-19 virus vaccine, although this may bring more side effects. Health agencies can also require people over a certain age to receive additional doses.
In addition to safety and effectiveness, there are some other factors to consider:
• How much do we need? Vaccination with only one dose is of course easier and faster. But this time we may need a multi-dose vaccine to obtain sufficient efficacy.
• How long can the effect of the vaccine last? Ideally, the vaccine will give you long-term protection. But we may eventually only get a vaccine that can only prevent you from getting sick within a few months (such as seasonal flu vaccine, which can protect you for six months). If this happens, this short-term vaccine may be used, but at the same time we will continue to develop more durable vaccines.
• How to store vaccine? Many common vaccines are usually kept at about 4 degrees Celsius-this is the average temperature of the refrigerator-so storage and transportation are easy. But RNA vaccines need to be stored at low temperatures as low as -80 degrees Celsius, which will make it more difficult to ship the vaccine to certain parts of the world.
I hope that the vaccine we get after 18 months will be as close to "perfect" as possible. But if it is not perfect, we will continue to improve. After humans have the COVID-19 virus vaccine, I think this vaccine may become part of the routine immunization plan for newborns.
However, after having the vaccine, there are still many problems to be solved. This is because:
We need to manufacture and distribute at least 7 billion doses of vaccine.
To stop this epidemic, we need to make this vaccine available to almost everyone on the planet. Previously, humans have never tried to transport something to every corner of the world. In addition, as I mentioned earlier, the manufacture and storage of vaccines are particularly difficult.
Unless we have a full understanding of the vaccines developed, we will not be able to understand much about vaccine production and distribution. For example, it is not clear whether we can use the existing vaccine factory to produce the COVID-19 virus vaccine.
What we can do now is to establish various types of vaccine factories to prepare for vaccine production. Each vaccine requires a different production plant. We need to prepare facilities for the production of each vaccine so that once the vaccine is developed, we can start producing the vaccine as soon as possible. This will cost billions of dollars. Governments need to quickly find a mechanism to fund this work. Our foundation is currently working with CEPI, the World Health Organization, and governments to solve financing problems.
Another question that needs to be decided is: who, when will the vaccine be obtained? The fact is, not everyone can get the vaccine at the same time. It takes months or even years to make 7 billion doses of vaccine (if it is a multi-dose vaccine, it may require 14 billion doses), and we should start distributing it after the first batch of vaccines is ready.
Most people agree that healthcare workers should be vaccinated first. But next, who will get the next one? The elderly? teacher? Workers doing important work?
I think low-income countries should be one of the first groups to get the vaccine, because in these places people will face a higher risk of death. The spread of the COVID-19 virus in poor countries will be much faster, because measures such as physical isolation will be more difficult to implement. More people are in poor health and more prone to complications, and weak health systems will make it harder for them to get the care they need. Prioritizing vaccination in low-income countries can save millions of lives. The good news is that we already have an organization in the Global Alliance for Immunization and Vaccinations (Gavi) that is specifically responsible for solving this matter.
For most vaccines, manufacturers will sign an agreement with the country where their factory is located so that the country can obtain the first batch of vaccines. It is unclear whether this will continue to be the case in this epidemic. I hope we can find a way that is fair to the whole world. Once we have solved this problem, WHO and national health authorities will need to develop a vaccine distribution plan.
However, we will eventually expand the scale of vaccine production so that the vaccine can be provided to everyone. Then, human society can return to normal. At the same time, I also hope that human society can make the right choices in the future to prevent it from falling into the current bad situation again.
The current situation may be a bit ugly, but there is a light at the end of the tunnel guiding us forward. We are doing the right thing to get the vaccine as fast as possible. At the same time, I urge you to continue to follow the epidemic prevention guidelines set by your government authorities. Whether we can successfully survive this disaster will depend on whether everyone can fulfill their responsibilities and ensure each other's safety.
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