Gao Fu: Vaccines can provide basic immunity, prevent severe illness and prevent death

Why did the new coronavirus appear? Are our vaccines effective in the face of mutant strains? Gao Fu, director of the Chinese Center for Disease Control and Prevention, recently analyzed and interpreted hot topics such as the new coronavirus epidemic>>

Editor’s Note:

At the opening ceremony of the 23rd Annual Conference of the China Association for Science and Technology, four speakers, Pan Jianwei, Lin Ming, Wan Jianmin and Gao Fu, delivered keynote speeches entitled "New Quantum Revolution", "Engineering Technology to Build World-Class Projects in the Main Economic Battlefield", "Developing Biological Breeding to Ensure Food Security" and "The Inspiration Brought to Us by Vaccine Research and Development Innovation: Asking Science for Answers", respectively focusing on the four directions of scientific and technological innovation facing the world's scientific and technological frontiers, the main economic battlefield, the major national needs, and the people's life and health.

【Speech Expert】

Gao Fu

Academician of the Chinese Academy of Engineering

Director of the Chinese Center for Disease Control and Prevention

"I can tell you clearly that the basic immunity provided by the vaccine can reduce our burden of disease." At the opening ceremony of the annual meeting of the China Association for Science and Technology held on July 27, Gao Fu, an academician of the Chinese Academy of Engineering and director of the Chinese Center for Disease Control and Prevention, delivered a keynote speech on the theme of "Inspiration from Vaccine R&D Innovation: Asking Science for Answers". In addition to reviewing the history of human struggle against viruses and taking stock of my country's vaccine injection and infectious disease prevention and control, he also analyzed and interpreted hot topics such as the new crown epidemic and the new crown vaccine.
"A vaccine should be able to prevent infection, so that you will not be infected after vaccination; second, prevent disease, so that you will not get sick even if you are infected; third, prevent transmission, so that you will not spread it to others even if you are infected; and finally, prevent severe illness and death. I can clearly tell you that vaccination can provide basic immunity, and such basic immunity can help us reduce the burden of disease."

Two viruses have been eradicated by humans

Humans have eliminated two viruses in an organized and planned manner, one is an animal virus and the other is a human virus.

Smallpox was once a very serious disease that affected people's lives and social stability, but it was eradicated in 1980. Another is the rinderpest virus, which can kill a large number of pigs, sheep and cattle. This is an animal virus that humans have eliminated through vaccines.

The first program implemented in my country was planned immunization, which began in 1978. The biggest difference is that during the planned immunization period, individuals have to bear certain expenses, but after joining the immunization program, the country will provide free immunization for all citizens.

In terms of research and development, China's vaccine research and development has a history of 100 years. As early as the 1950s after the founding of New China, seven major biological product research institutes were established. As time went by, a national immunization planning expert committee was established in 2019 to formulate various plans for vaccination.

There are two words to note here: one is "eradicate" and the other is "eliminate". If the virus disappears from the earth, it is called eradication; if it only survives in a certain area, it is called elimination. Therefore, our country has eradicated smallpox and eliminated polio.

my country controls infectious diseases through vaccination

A good vaccine requires four conditions: it must be safe, effective, of controlled quality, and accessible. my country has made great progress in research and development, production, supply, and supervision in recent years. The variety and output of vaccines are increasing, the ability to develop vaccines is also increasing, and non-immunization program vaccines, also known as Class II vaccines, are also growing year by year.

From 1950 to 2020, our country has effectively controlled infectious diseases through vaccination. For example, measles, a disease with an infection rate of nearly 80%-90%, has been effectively controlled through vaccination, with the number of infections decreasing every year.

▲my country has effectively controlled hepatitis B through vaccination. The picture shows a schematic diagram of the hepatitis B vaccine. Image source: Visual China

The infection rate of hepatitis B in China used to be 10%, but now it has dropped to 3‰. In 1992, 2006 and 2014, nationwide epidemiological surveys on hepatitis B were conducted, and the number of serum-positive people has been declining year by year. This is also a great achievement of the vaccine.

Vaccines have also played an important role in extending life expectancy: when China was first liberated in 1949, life expectancy was 35 years old; in 2019, it reached 77.3 years old. During this period, neonatal deaths have been declining and life expectancy has been increasing. These are all due to the immunization program and other comprehensive measures.

COVID-19: Gray rhino or black swan?

Next, let's discuss the COVID-19 vaccine. Why did the COVID-19 virus appear? In fact, the emergence of coronaviruses is not surprising. Coronaviruses can be found in chickens, horses, cattle, sheep, pigs, and domestic cats and dogs. Their biggest feature is that they are particularly prone to recombination. A fragment can be recombined from different coronavirus sources, and then a new virus will be formed.

On October 18, 2019, Johns Hopkins University in the United States organized a drill with the support of the Gates Foundation and the World Bank. I was invited to participate. The disease in the drill was called coronavirus-associated pneumonia syndrome. So the new coronavirus, scientists have long predicted that it might come. Its spread is completely a "gray rhino" event for professionals. For the public, because they don't understand the situation, they feel it is a "black swan" event.

The International Pandemic Monitoring Committee's 2019 annual report also stated that the coronavirus will be the next pandemic virus in human history, and humans must be prepared. So are humans ready now? The conclusion is no.

We can foresee that in the future there will be eighth and ninth types of coronaviruses that cause human infection. This is why we are looking for a universal vaccine to protect against various possible coronaviruses.

▲The coronavirus epidemic will be one of the biggest challenges facing human society in the future. The picture shows the restoration of the structure of the new coronavirus. Image source: CDC

Let’s review the seven coronaviruses that infect humans. In 1937, humans had isolated the infectious bronchitis virus of chickens, which is a coronavirus, from a virus that infects chickens. In 1965, a coronavirus that infects humans appeared, called HCoV-229E. In 1967, HCoV-OC43 was isolated. Later, HCov-NL63 was isolated, NL stands for Netherlands. In the same year, HCoV-HKU1 was discovered, which was isolated by the United University of Hong Kong, also known as Hong Kong University No. 1.

In the past, it was believed that HKU1 was discovered in 2004, but Brazilian scientists found that the virus had actually been stored in a laboratory refrigerator in 1995, so the name HKU1 was wrong. So we have repeatedly emphasized that no one should pass the buck, and tracing the origin cannot be politicized. Tracing the origin is a scientific issue.

Vaccines and virus mutations

Finally, let's talk about the COVID-19 vaccine. Why is China at the forefront of COVID-19 vaccine research and development? This is a virtuous cycle brought about by the long-term investment in pathogenic microorganisms and immunology in China in recent years. The timely sharing of viral genome sequencing results also bought time for vaccine research and development around the world.

my country's institutional advantages of joint prevention and control and mass prevention and control also ensured the development of vaccines. A special vaccine team was set up at the first time and five routes were actively deployed. The Wuhan Institute of Virology provided Sinovac Biotech with a P3 laboratory for early vaccine production, so the vaccine was developed in two or three months.

▲July 28, 2021, Guangzhou, Tianhe Sports Center vaccination site, medical staff vaccinated students. Image source/People's Vision

It is worth mentioning that during this epidemic, scientific and technological means and methods provided strong support in controlling infection, virus tracing, disease treatment, vaccine and drug research and development, and resumption of work and production. A successful scientific and technological war against the epidemic was a profound manifestation of "innovation-led, self-reliance and self-improvement". Vaccine research and development can be said to be a model. We have been handling this epidemic in an open, transparent and responsible manner in accordance with the instructions of the General Secretary.

Currently, vaccines around the world are divided into seven categories: Inactivated vaccines are more familiar to everyone, with an inactivated virus and a little adjuvant. Attenuated vaccines are under development and have not yet entered clinical trials. Protein subunit vaccines were developed by a team at the Institute of Microbiology, Chinese Academy of Sciences, and are currently being clinically used in China and Uzbekistan. Viral vector vaccines, adenovirus vector vaccines, and influenza virus vector vaccines all work on the principle of using a virus to bring in the immunogen. Nucleic acid vaccines are currently the mRNA vaccines that everyone is particularly familiar with.

China currently has seven vaccines, five inactivated vaccines, one adenovirus vector vaccine, and one protein vaccine.

About 26% of the world's population has received the first dose of the vaccine, and the global progress is good. However, the devil is always stronger than the good. Now the relationship between us humans and the pathogens we face is like the relationship between "cat and mouse". When we were developing vaccines and injecting them, a batch of mutants also appeared. In the face of such mutants, will our vaccines work? This is a question that everyone has been thinking about.

The best thing a vaccine can do is to prevent infection, so that you will not get infected after getting it; secondly, to prevent disease, so that you will not get sick even if you are infected; thirdly, to prevent transmission, so that you will not spread it to others even if you are infected; and finally, to prevent severe illness and death. I can tell you clearly that vaccination can provide basic immunity, which can help us reduce the burden of disease.

Now, the third wave of the COVID-19 pandemic has begun around the world. Take the UK as an example. After vaccination, the number of deaths in the third wave was significantly lower than that in the second wave, with the same number of cases. Therefore, today's vaccines can prevent severe illness and death. Now we call on the world to share vaccines.

It has been more than 100 years since the discovery of tuberculosis, and there is no good vaccine at present; there is still no vaccine for HIV. The Chinese started vaccinating against human pox a long time ago, but the British started vaccinating against cowpox, which promoted the development of immunology and led to the eradication of smallpox worldwide.

The development of the COVID-19 vaccine has also triggered our thinking. That is, while we are practicing, we must also think about the theory behind it. We must be good at thinking, summarizing, and finding theories and hypotheses from chaotic practices. Finally, we must prove that it is a theory and truly ask science for answers. Only then can we have the possibility of defeating the disease through vaccines. ■

Compiled by reporter Zhao Tianyu Edited by Liu Zhao

New Media Editor/Lv Bingxin Proofreader/Li Yunfeng

Produced by: Science Central Kitchen

Produced by: Beijing Science and Technology News | Science Plus Client

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