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The question I have been asked the most these days is: When will the world return to its state before the New Corona Virus pandemic last December? My answer is always the same: when we get a near-perfect special effect medicine, or when almost everyone on the earth is vaccinated with the new crown vaccine.

The former is unlikely to be realized in the short term. We need a treatment that is 95% efficient to contain the epidemic. For now, most drug candidates are far less powerful. They can save many lives, but they are not enough to allow us to return to normal life.

So, we can only hope for vaccines.

Forming a wide range of new coronavirus immunity has become the most urgent task for humans. In fact, if you wantTo return to normal life, we need to develop a safe and effective vaccine that needs to produce billions of doses and supply them all over the world, and all this needs to be achieved as soon as possible.

It sounds discouraging because it is really difficult. The Gates Foundation is the world’s largest vaccine funder, but the challenges we face this time are far greater than any previous work. This requires unprecedented global cooperation. But I know this will eventually succeed. There is no other choice.

The development of the new crown vaccine is racing against time. Here are the things you need to know.

The world is at an unprecedented speed

Develop a new coronary pneumonia vaccine

Dr. Anthony Fudge believes that it takes about 18 months to develop a new coronary pneumonia vaccine. I agree with him that although it may only take 9 months, it may be as long as two years.

Although 18 months may sound long, it will be the fastest new vaccine developed by scientists so far. It usually takes about five years to develop a vaccine. Once you choose a disease as a target, you must develop a vaccine and test it on animals. Next, you can conduct human trials to test the safety and effectiveness of the vaccine.

Safety and effectiveness are the two most important goals of each vaccine. Safety is its literal meaning: Is it safe to vaccinate people? Some minor side effects (such as mild fever or pain at the vaccination site) are acceptable, but you do n’t want people to get sick because of the vaccination.

Efficacy measures how effective the vaccine is at you. Although ideally you want a vaccine to be 100% effective, many vaccines are not so perfect. For example, the effective rate of the flu vaccine this year is about 45%.

In order to test the safety and effectiveness of vaccines, each vaccine undergoes three stages of clinical trials:

• The first phase of the clinical trial is a safety trial in which a small group of healthy volunteers are vaccinated against the candidate vaccine. You can try different doses, the purpose is to produce the strongest immune response with the lowest effective dose without serious side effects.

• After determining a set of plans, you will enter the second phaseIn clinical trials, it will tell you how effective the vaccine is in the vaccinated population. This time, hundreds of people will be vaccinated, and this group should include people of different ages and different health conditions.

• Next, in a phase III clinical trial, you will have thousands of people vaccinated. This is usually the longest stage because it occurs under so-called “natural disease conditions”. You vaccinate a large group of people who may have been exposed to the risk of infection with the target pathogen, and then see how much the vaccine can reduce the number of patients.
  

  After the vaccine passes the above-mentioned phase III clinical trials, you will also need to have a vaccine production plant and submit the vaccine to the World Health Organization and various government agencies for approval.

  This process is suitable for most vaccines, but the conventional development schedule is obviously not suitable for new crown vaccines. Every day we save from this process will have a huge impact on the world, not only saving lives, but also reducing the economic losses of trillions of dollars.

  Therefore, in order to speed up this process, vaccine developers are compressing time. From the picture below, we can see how we did it.
  

  In the traditional process, these steps are carried out in order to solve key problems and unknown factors. At the same time, it also helps to reduce financial risks, because the development of a new vaccine is expensive. Many candidate vaccines failed in the end, which is why companies need to wait until the success of the previous step is clear before continuing to invest in the next step.

  For the new crown vaccine, development funds are not a problem. Governments and other institutions in various countries-including our foundation and a “Pepidemic Prevention Innovation Alliance” (Coalition for Epidemic Preparedness Innovations, CEPI) A great organization-has made it clear that it will support vaccine development at all costs. Therefore, scientists can carry out several development steps in parallel tosave time. For example, the private sector, government, and our foundation will begin to identify facilities that produce different potential vaccines. Even if some facilities are not used in the end, that ’s okay. In order to shorten the vaccine production process, this is only a small price.
  

  Fortunately, compressing clinical trial time is not the only way to shorten the vaccine development cycle from five to 18 months. Another measure we are about to take is to experiment with many different methods simultaneously.

  Dozens of vaccine candidates are under preparation

  As of April 9, there are 115 different new coronary pneumonia vaccine candidates in development. I think 8 to 10 of them look promising. (In spite of this, our foundation will pay close attention to all other vaccines, so as not to miss out those with technology. Potential vaccine) .
  

  The most promising vaccine candidates have adopted various methods to protect the human body from the new coronavirus. What exactly does this sentence mean? Let us first understand how the human immune system works.

  When a pathogen enters the body, your immune system produces antibodies. These antibodies attach to substances called antigens on the surface of microorganisms and send an attack signal to your body. Your immune system records every type of microorganism it has defeated, so you can quickly identify and destroy them before the invader makes you sick.

  The vaccine can avoid this entire process, it can teach your body how to defeat the pathogen without getting sick. The two most common types (and the type you may be most familiar with) are inactivated vaccines and live vaccines. Inactivated vaccines contain killed pathogens. Live vaccines are made from live pathogens with reduced toxicity (or “attenuated”). They are very effective, but they are more prone to side effects than similar inactivated vaccines.

  Inactivated and attenuated live vaccines are what we consider to be “traditional” methods. There are many candidate vaccines for these two types of new crowns. The reason is simple: their technology is mature. We know how to test and manufacture them.

  But their disadvantage is that it is time-consuming to manufacture. Each dose of vaccine requires a lot of raw materials, most of which are biological materials, which means you need time to cultivate them.

  This is why I am particularly excited about the two new methods currently adopted by some candidate vaccines: RNA vaccine and DNA vaccine. If any new method succeeds, we allCan provide the vaccine to the world faster (for simplicity, I will only explain the RNA vaccine, the principle of the DNA vaccine is similar, only using different genetic materials and vaccination methods).

  Our foundation has been supporting the development of the RNA vaccine platform through our own funds and CEPI for nearly a decade. We originally planned to use it to develop vaccines against diseases that affect the poor (such as malaria), but now it seems that it may be one of the most promising options for combating new coronary pneumonia. The first candidate vaccine to start human trials is an RNA vaccine made by a company called Moderna.

  The working principle of RNA vaccines is not to inject pathogen antigens into the human body, but to provide the human body with the genetic code needed to produce antigens. When antigens appear outside the cells, your immune system will attack them and learn how to defeat future invaders in the process. Essentially, it turns the human body into its own vaccine production department.

  Because RNA vaccines let your body do most of the work, it does n’t require too much production materials to make them, and production can be faster. However, there is still a problem: we are still not sure whether RNA is a viable platform for vaccine development. Since the new crown RNA vaccine will be the first RNA vaccine to be marketed, we must prove that the RNA platform itself is feasible and can generate immunity. This is a bit like building a computer system and the first software in the system at the same time.

  Therefore, even if the RNA vaccine is expected to succeed, we must continue to seek other possible methods. We do not yet know what the new crown vaccine will look like. Before that, we must go all out and try as many methods as possible.

  It may not be the perfect vaccine, but it ’s okay

  The smallpox vaccine is the only vaccine in the world to eradicate a disease from the earth, but the process of getting smallpox vaccine is a bit painful. It will leave scars on the arm of the inoculated person. One in three people will only stay at home temporarily due to side effects, unable to go to school or work. There will also be a small number of people who cannot be ignored that will produce more serious reactions.

  The smallpox vaccine is far from perfect, but it has fulfilled its mission. The new crown vaccine may be the same.

  If you want to design a perfect vaccine, we want it to be 100% safe and effective. You only need one dose to get lifelong immune protection. And the storage and transportation of vaccines should be very convenient. I hope that the new crown vaccine will have all these features, but given our schedule, it may not be all-encompassing.

  As I mentioned earlier, the two main points of the vaccine are safety and effectiveness. Since we may not have the time to conduct many years of research, we will have to conduct a strong first-phase safety trial and good real-world data, and ensure that we have sufficient evidence that the vaccine is safe to use.

  We still have some room for effectiveness. I estimate that a vaccine with at least 70% effectiveness is enough to contain the epidemic. Vaccines with 60% effectiveness are available, but local outbreaks may still be seen. Any vaccine that is less than 60% effective is unlikely to generate sufficient group immunity to prevent the spread of the virus.

  The biggest challenge is to ensure that the vaccine is also effective for the elderly. The older the age, the weaker the vaccine. Your immune system, like other parts of your body, will age with age, and the rate of identifying and attacking intruders will be slower. This is a big problem for the new crown vaccine, because the elderly are also the most susceptible to the new crown virus, and we need to ensure that they are protected.

  As a vaccine for the elderly as well, the shingles vaccine solves the above problems by increasing the effectiveness of the vaccine. For the new coronavirus, we can do similar things, although this may bring more side effects. The health department can also vaccinate people over a certain age.

  In addition to safety and effectiveness, there are several factors to consider:

  • How many doses should be vaccinated? Only one dose of vaccine is needed, which is relatively more convenient and faster. But we may need to receive multiple doses of vaccines to achieve sufficient efficacy.
    

  • How long can the vaccine efficacy be maintained? Ideally, vaccines can provide lasting protection. But in the end we may get a vaccine that can only protect you for a few months (similar to the seasonal flu vaccine, the immunization time is about 6 months). If this is the case, we are likely to use short-term effective vaccines while studying longer-lasting vaccines.

  • How to store the vaccine? Many common vaccines need to be stored at 4 degrees Celsius, which is about the temperature of a general refrigerator, so storage and transportation are relatively simple. But RNA vaccines need to be stored at lower temperatures, possibly as low as minus 80 degrees Celsius, and it will become more difficult to transport them to certain parts of the world.
    
    

    I hope that the new crown vaccine born 18 months later will be as close to “perfect” as possible. Even if not, We will continue to work hard to improve it. After that, I think the new crown vaccine will become part of the routine immunization plan for newborns.

    Even with the vaccine, we still need to solve some important problems, that is because …

    We need to produce and distribute at least 7 billion doses of vaccine

    In order to contain the pandemic, we need to ensure that almost everyone on the planet can be vaccinated. Sending something to every corner of the world has never happened in the past. At the same time, as I mentioned before, the production and storage of vaccines is also very difficult.

    Until we know which vaccine will eventually be used, we cannot determine how to produce and distribute the vaccine. For example, can we use the existing vaccine factory to produce the new crown vaccine?

    What we can do now is to build factories for various types of vaccines. Each type of vaccine requires a different production plant. We need to prepare equipment for the production of various vaccines to ensure that production begins as soon as one or more vaccines are developed. This will cost billions of dollars, and governments need to quickly find a mechanism to fund it. The Gates Foundation is raising funds with CEPI, the World Health Organization and governments.

    There are also discussions focused on who will be vaccinated and when. The reality is that we cannot allow everyone to be vaccinated at the same time, but it takes months or even years to produce 7 billion doses of vaccines (if multiple doses are given, it may even be 14 billion doses) The first batch of vaccines was distributed immediately.

    Most people agree that health workers should give priority to vaccination. But who should be vaccinated next? The elderly? teacher? People working in key positions?

    I think people in low-income countries should be vaccinated in the first batch because they face a higher risk of death. Because measures such as physical isolation are more difficult to implement, the new crown epidemic will spread faster in poor countries. More people have poor basic health conditions, making them more prone to complications, and in a weak health system, they have difficulty getting the treatment they need. Providing vaccines for low-income countries can save millions of lives. The good news is that we already have professional organizations like the Global Alliance for Vaccines and Immunizations (Gavi) working in this area.

    For most vaccines, the vaccine manufacturer will sign an agreement with the country where the factory is located to ensure that the country gets the vaccine first. It is unclear whether this will happen. I hope we can find a way to present to the world on a fair basisProvide vaccines. Once we are more clear about the progress of our current work, the World Health Organization and local health departments will need to develop a vaccine distribution plan.

    Finally, we will expand the scale of production so that everyone on the planet can be vaccinated. After that, we can return to normal life and hope to avoid falling into the same predicament again through wise decisions.

    Although the road ahead is confused, the light is ahead. We are taking the right approach to get an effective vaccine as soon as possible. At the same time, I urge everyone to continue to follow the guidance of the local health department. Whether we can survive the epidemic safely depends on whether everyone can do their part to ensure the safety of themselves and others.