How many new coronal vaccines are needed for global population immunization?

Half a year later, although countries have introduced social isolation, home office and other control measures, the new epidemic is still spreading around the world at the rate of 1.5 million new cases per week. In some areas that were already under control, the epidemic is coming quietly. In such a situation, the research and development of new coronal vaccine has become the world’s life-saving straw to overcome the epidemic situation.

at present, there are at least 165 candidate vaccines under development in the world, of which 37 have entered the stage of clinical trials. If we are optimistic, we may see 5-7 successful vaccines in a year.

the principle of vaccine is to stimulate the immune response of human body through vaccination, so that the vaccinated individuals can be free from virus infection. When the vaccination population reaches a certain scale, the virus will lose the way of hiding and spreading in the crowd, and “group immunity” will be realized. It follows this basic logic to fight the new crown with a vaccine.

how many vaccines are needed to achieve global mass immunization and eliminate the new coronavirus? According to Johns Hopkins University experts estimate, generally speaking, when 70-90% of the population is immunized against the virus, the basic conditions for group immunity are reached. In other words, according to the global population of 7.5 billion, 5.25-6.75 billion people need to be immunized; considering that sometimes two doses of vaccine can work, the world needs at least 10 billion doses of new crown vaccine.

what is the concept of 10 billion doses of vaccine? The global vaccine production is mainly concentrated in GSK, Johnson & Johnson, Pfizer and Sanofi, as well as several manufacturers in India and China.

even if all the existing vaccine production lines are used to produce the new crown vaccine, it can not meet the global demand. Moreover, in order to avoid the outbreak of other infectious diseases, the conventional vaccine production must continue. However, the production capacity of major companies is nearly saturated. According to Sanofi group, without reducing the production capacity of influenza vaccine, the company can produce at most 600 million doses of new coronal vaccine; however, if the new vaccine needs high-dose antigen, it may only produce 100 million doses of new coronal vaccine. On the basis of not affecting the immunization of other vaccines, even the delivery of new coronal vaccines in batches also requires new production facilities, which is not easy.

the cost of building a vaccine factory is about US $50 million to US $700 million according to different configuration requirements. According to the U.S. Department of defense estimates that the full cycle cost of a 25 year plant that can produce three vaccine products is about 1.56 billion US dollars, and generally takes seven years for design, construction, acceptance and production preparation.

Pfizer’s vaccine plant in the United States once spent $600 million and took five years to build. The Serum Institute of India, a major producer of vaccines for developing countries, estimates that it will cost $164 million to build a plant to produce the new crown vaccine. Johnson & Johnson is considering investing $1 billion to build a new crown vaccine plant. It can be seen that even if the research and development is successful, the initial investment in the production of new crown vaccine is not a small amount.

large scale demand for raw materials is another factor testing the vaccine supply chain. Take the vial containing the vaccine as an example. A seemingly humble glass bottle has four layers of different materials on its surface. Because vaccine storage often has many different requirements, and sometimes even needs to be stored at – 70 ℃, a simple glass container is not up to standard.

at the beginning of the epidemic, Johnson & Johnson group had ordered 250 million vials from Schott AG, the world’s largest medical glass company. However, according to Schott AG, even if more than 1 billion bottles were received, their production capacity was only half of the capacity. The U.S. government has just decided to invest $204 million in Corning to expand the vaccine vial production line.

generally speaking, the cost of a vial is about US $1, but in the face of sudden demand for vaccines, the future supply and price are still unknown. The shortage of glass bottles is only a small step in the expansion of vaccine production capacity. If we want to expand the vaccine supply chain in an all-round way, there are still many links to be taken care of.

the prediction of capacity demand is generally based on a series of assumptions, including virus mutation, transmission rate and whether there are new preventive measures, etc.

among them, the transmission rate of virus is particularly critical. If the transmission rate drops sharply, the new epidemic situation will gradually decline or even disappear, and the demand for vaccine will also decline; if the transmission rate rises sharply, human beings may realize mass immunization in the large-scale spread of the virus, and there is no need for vaccination.

the uncertainty generated by these assumptions means huge investment risk for enterprises. After all, when SARS in 2003 and H1N1 virus in 2009 arrived, there was a “vaccine fever” that disappeared with the improvement of the epidemic situation.

in addition, this series of investment decisions also need to race against the uncertainty of R & D. At present, hundreds of vaccines based on several different technologies are being developed. When vaccines with different technologies are produced on a large scale, the workshops and production lines required are quite different. Therefore, in the face of high cost and high uncertainty, vaccine enterprises generally need more information to make investment decisions. Predicting the technology used in the successful vaccine development and investing in plant construction ahead of time to arrange production capacity is undoubtedly like scraping a lottery ticket of hundreds of millions of dollars.

but the epidemic situation is imminent. It is estimated that the global GDP may decline by 5.2%, and the annual economic loss may be as high as 3.8 trillion US dollars. Moreover, tens of thousands of lives will be lost every month If we wait until the R & D is successful and then lay out the production facilities, it will delay another one to two years, and the loss will be immeasurable during this period.

in order to solve the epidemic situation as soon as possible, maybe we will have to arrange in advance when we know that some investments may fail or over invest. Who will bear the capital risk is also a factor to be considered in the early stage.

the transportation of new coronal vaccine is another difficult problem. In terms of capacity, Emirates estimates that a Boeing 777 Freighter can carry about 1 million doses of vaccine. In terms of two courses of treatment, it would take about 8000 freighters to transport eight billion doses of vaccine to protect half of the world’s population. Due to the sharp decline of global freight capacity during the new crown period, the organization of such a scale of transport capacity needs to be deployed on a global scale.

in terms of logistics technology, unlike the transportation of masks, the transportation of vaccines requires an advanced cold chain logistics system, which makes logistics more difficult exponentially. Generally speaking, vaccine transportation needs to guarantee the low temperature condition of 2-8 ℃ throughout the whole process. Some vaccines even need to be stored at – 80 ℃. If there is a slight deviation, a batch of vaccines may be lost.

a high-level cold chain system is not easy to achieve in developed countries. In sub Saharan Africa, only 28% of medical places have stable power supply, sometimes they need camels and horses, and even have to rely on manpower to transport vaccines. This makes the demand for cold chain systems a gap in underdeveloped regions before vaccine delivery.

facing the urgency of time, the high cost and the high degree of uncertainty in the process, only the global gathering of resources and sharing the risks is the most efficient and possible way out.

in this context, the World Health Organization, the global alliance for vaccines and immunization and the Alliance for innovation in epidemic prevention jointly called for the launch of the covid-19 global vaccine facility to coordinate and accelerate the development, production and fair delivery of new coronavirus vaccines, so as to enable the world to realize new coronal immunization as soon as possible. Covax facilities will invest resources for the whole chain of vaccination of new coronal vaccines, including investment in the construction of factories in advance, so as to put them into mass production immediately after the successful development of vaccines.

according to the current plan, the covax facility aims to deliver 2 billion doses of vaccine by the end of 2021, and ensure that all countries participating in covax provide enough vaccine to protect at least 20% of their population, regardless of whether the participating countries have sufficient capacity to pay.

for low resource countries, covax ensures their vaccine supply, so that they do not lose the chance of new crown immunization because of lack of bargaining power. For high resource countries, covax helps them reduce the risk of betting on single vaccine development.

after all, any single vaccine has a high risk of failure. If you place an order unilaterally, it will be like buying a lottery ticket with high risk and high investment of several billion dollars. With the same or less investment, the covax facility can obtain the final supply of vaccine. Although it can only cover 20% of the population, it is enough to guarantee the supply of vaccine for personnel in important social positions such as medical staff.

because covax has gathered funds from all over the world, it has several kinds of vaccine options with multiple development methods, and has better anti risk ability than a single vaccine order. Through the principle of sharing risks and ensuring distribution, covax also provides a driving force for high resource countries to participate in international cooperation.

Currently, a total of 160 countries have committed to join the covax facility, covering more than 60% of the world’s population and more than half of the G20 countries. Participating countries can purchase vaccines for their own countries through covax facilities, and help low-income countries obtain vaccine distribution through grants and other forms.

at the same time, covax facilities will also use the advance purchase commitment for vaccine manufacturers to promise vaccine procurement in advance, so as to guarantee the manufacturers’ R & D and capacity building motivation. Since its release in June, the AMC of the new crown vaccine has raised $600 million as of July 15. Although there is still a certain gap from the initial target of $2 billion, considerable progress has been made.

GAVI has been committed to promoting vaccine immunization in poor countries. In 2000, GAVI had not yet been established. The vaccine coverage rate in low-income countries was 59%, while that in high-income countries was 90%. There was a 31% gap between the two. By 2020, 18 years after GAVI was established, the vaccine coverage rate in low-income countries has risen to 81%, while that in high-income countries is 95%, with a gap of only 14%. In 2019 alone, 65 million poor children will be vaccinated with GAVI’s support.

AMC mechanism is an essential “magic weapon” of GAVI in promoting vaccine immunization around the world. AMC was launched in 2009 and was first used in the procurement of pediatric pneumonia vaccine. At that time, the governments of Italy, the United Kingdom, Canada, Russia, Norway and the Gates foundation were involved. In the past 10 years, 225 million children from 60 low-income and low-income countries were vaccinated against pneumonia, which averted about 700000 child deaths. GAVI’s past experience in AMC will provide guidance for the international community in the allocation of new coronal vaccines and promote vaccine equity.

in the aspect of vaccine transportation, the world bank is strengthening the cold chain logistics capacity of developing countries through the esmap effective and clean cooling project. At the same time, the world bank is also organizing a power supply project for Sub Saharan Africa to provide stable power for medical facilities with distributed photovoltaic and battery parallel solutions. From now on, strengthening the cold chain logistics capacity of countries can not only help countries to prepare for vaccination of new coronal vaccine, but also bring convenience for other vaccines, which can be described as a lot of benefits.

recently, many countries have signed vaccine supply contracts with pharmaceutical enterprises