Gao Fu: COVID-19 vaccines against mutant strains should be approved for use as soon as possible

Interview with Gao Fu: COVID-19 vaccines against mutant strains should be approved for use as soon as possible

　　At the press conference of the joint prevention and control mechanism of the State Council on January 14, the National Health and Medical Commission notified that from December 8, 2022 to January 12, 2023, the cumulative number of deaths related to the new coronavirus infection in hospitals across the country exceeded 59,000. example.

The peaks of fever clinics and emergency departments across the country have passed, but the number of critically ill patients in hospitals is still at a high level.

　　At the same time, according to the press conference of the joint prevention and control mechanism of the State Council, since October last year, a total of 16 local cases of XBB have been reported in China. From the perspective of imported risks, the risk of local related cases caused by XBB and its sub-branches in the future is relatively high.

Starting from January 7, the 40-day Spring Festival travel migration with the participation of more than 2 billion people has also started. This is the largest population movement during the Spring Festival in the past three years.

　　Will this trigger a new spike in infections?

Will new mutant strains appear in China in the future, and when will the new crown pandemic end?

Focusing on related issues, Gao Fu, academician of the Chinese Academy of Sciences and former director of CDC, accepted an exclusive interview with China News Weekly.

Second wave peaks in remote rural areas

China News Weekly: Will there be a new peak of infection during the large-scale population movement during the Spring Festival travel season?

　　Gao Fu: In provinces and cities represented by Beijing, Henan, Jiangsu, and Anhui, the peak of infection in cities has passed.

In Beijing, going to the hospital is still a bit crowded recently, but the number of patients seeing a doctor has dropped compared with the early stage of this round of epidemic.

Some county towns and rural areas have also passed the peak of infections.

　　Now the main virus strains prevalent in China are BF.7 and BA 5.2 branches. If there is already a high infection rate in an area, the probability of repeated infection in the short term is very small.

　　However, for areas that have not yet entered the peak of infection, such as some remote rural areas, due to the return of people to their hometowns during the Spring Festival, there may be a peak of infection.

This wave of infections will not be higher than the peak of the first wave after the adjustment of the epidemic prevention policy.

However, the new infection peak is likely to appear in places where there is a shortage of doctors and medicines, and less than 10% of the rest of the country have not completed full vaccination. There will be medical runs in these areas. Therefore, we still call on everyone to reserve the most important medical resources for those who have Elderly high-risk groups with underlying diseases.

China News Weekly: How long will this wave of infection peaks in rural areas last?

　　Gao Fu: I think it will last until March.

During the Spring Festival, because there are more appeals, everyone may pay more attention to it.

Once the Spring Festival is over and everyone relaxes their awareness of prevention and control, there may be a small peak of infection from February to March.

China News Weekly: During the Spring Festival, what measures should we take to suppress the peak?

When will the peak of severe cases in many places see an inflection point?

　　Gao Fu: If you haven't had a booster shot, and you haven't experienced infection, you should get the vaccine as soon as possible.

Non-drug interventions, such as wearing masks, washing hands frequently, and gathering less, must be persisted.

On the way back home during the Spring Festival, try to wear N95 as much as possible.

Where conditions permit, antiviral drugs should be prepared as much as possible.

　　Regarding the peak of severe cases in this round of the epidemic, it turned out that everyone believed that the inflection point could be seen around the Spring Festival.

But now because of comprehensive intervention measures, it is likely to be delayed by another 20 days to one month from the peak of infection, and the inflection point may be reached in early February.

The possibility of emergence of more pathogenic strains cannot be ruled out

China News Weekly: From October last year to the present, a total of 16 local cases of XBB have been reported in China, all of which are evolutionary branches of XBB.1.

So far, no indigenous cases of XBB.1.5 have been found.

Will XBB cause a new peak of infection in China?

　　Gao Fu: In the United States, XBB1.5, a branch of XBB, has become a strain with increasing prevalence.

XBB.1.5 has obvious immune escape, almost equivalent to a brand new virus.

If XBB finally becomes popular in China in March and April, from the perspective of vaccine and immunity, everyone may be infected again.

However, the existing vaccines can also provide a certain basic protection against severe illness and death after infection with XBB.

　　After XBB enters the country, if the popular BA.5 and BF.7 can provide some cross protection for XBB, XBB may not be able to start, and this possibility cannot be ruled out.

　　Viruses of different subspecies are also competing for survival.

BQ.1 abroad is currently the mainstream strain, and it is uncertain whether the main domestic strain will be XBB or BQ.1 in the future.

　　In addition, it is especially important to note that the basic immunity levels of China and many other countries in the world are different.

Foreign countries have experienced multiple rounds of natural infections such as Delta, Omicron BA.1, BA.2, and BA.5. Many people have also received the fourth dose of the new crown vaccine against the Omicron strain.

In contrast, China has not previously experienced large-scale natural infections, which can cause a strain to behave differently domestically than in other countries around the world.

As time goes on, by May and June, it is very likely that the same strain is circulating in China as in other countries around the world.

China News Weekly: How to treat the secondary infection of the new crown scientifically?

　　Gao Fu: Human vaccination is actually forcing the virus to mutate.

On the one hand, after vaccination, many deaths can be avoided. On the other hand, because the vaccine has established an immune barrier, the virus will also escape, making it easier for new strains to emerge.

　　In a sense, today's XBB and the prototype strain discovered in early 2020 are two completely different strains.

From the perspective of immunity, the BA.1 subtype of Omicron is also quite different from today's XBB.

　　As far as the new coronavirus is concerned, at least three types of serotypes can be divided at present. The early prototype strain and Delta are counted as one, and they can provide cross-protection.

The early subtypes of Omicron count as one, and XBB counts as one.

The so-called secondary infection, in essence, means that the cross protection between different subspecies is weak.

China News Weekly: In the process of continuous infection in China, will there be a new mutant strain?

What will be the future mutation trend of the new coronavirus, for example, how will the pathogenicity and transmissibility change?

　　Gao Fu: Continued immune escape is a trend.

For example, compared with XBB, XBB.1.5 has only one key amino acid change in its receptor binding domain (RBD), which makes the existing vaccines around the world almost completely ineffective.

　　Theoretically speaking, as far as the relationship between viruses and humans is concerned, the virulence of viruses will become weaker and weaker.

From the early prototype strains to today's XBB, the transmission of the virus is increasing, but the pathogenicity is obviously decreasing.

In October last year, researchers at Boston University in the United States published a study in which they inserted some genes of the Omicron strain into the prototype strain for recombination.

The study found that the death rate of mice infected with the newly recombined virus was 80%, and the death rate of mice infected with the prototype strain was 100%.

This shows that in animal experiments, the pathogenicity of the new coronavirus is reduced.

In other words, as far as the internal evolution of the new coronavirus is concerned, it is very unlikely that a more virulent strain will emerge.

　　However, if a brand new coronavirus spills from animals and then spreads to humans, which we professionals believe may happen at any time, a more virulent strain may emerge.

Moreover, coronaviruses are easy to recombine. For example, XBB is recombined from two branches of BA.2 and has weak virulence.

However, if different coronaviruses are recombined, it is possible to emerge a more virulent and completely new virus.

　　The immunity situation in China is different from other countries, and the new coronavirus may have different mutations than in other countries.

From a scientific point of view, we hope to synchronize with the degree of immunity of the world.

We must closely monitor virus mutations, conduct sequencing, and make data public.

In addition, the data of disease control systems and medical institutions at all levels should be better coordinated and integrated.

I hope to establish a national coronavirus monitoring center, and then play a game of chess with the world to monitor the virus well and continue to increase the coverage of monitoring.

China News Weekly: Regarding the pathogenicity of the new crown virus, how can the public have a more scientific understanding? Previously, the public was hotly discussing that the proportion of asymptomatic patients is very small, and the proportion of pneumonia is not low?

　　Gao Fu: First of all, the virulence of Omicron has decreased, but it has not decreased enough to be used as a vaccine.

After all, Omicron is still a new crown virus, wolves still eat sheep, and vulnerable and high-risk groups will suffer severe illness and even die.

　　Therefore, there can be neither "coronaphobia" nor "light crown syndrome".

For the current mainland China, the most relevant data on severe cases and mortality are the reality of the early stage of the fifth wave of the epidemic in Hong Kong last year.

China News Weekly: In addition to the new coronavirus, so far, including MERS and SARS, there are 6 kinds of coronaviruses that can infect humans.

What are the main differences between the new coronavirus and several other coronaviruses?

So far, scientists have been dealing with the new coronavirus for three years, what else is still unknown?

　　Gao Fu: The previous coronavirus did not mutate as fast as the new crown.

From the perspective of immune escape, the new coronavirus is more and more inclined to influenza virus, but the evolution rate has not surpassed influenza.

Moreover, during the mutation process of the new coronavirus, the mutations are often key points.

　　Regarding the new coronavirus, there are still too many unanswerable scientific questions. For example, it has the same receptor binding domain as the SARS virus, but why it does not disappear in the crowd like the SARS virus, and where did the new coronavirus come from? Why is immune escape so powerful? Scientists must continue to explore.

The use of antiviral drugs should pay attention to time and space

China News Weekly: One of the important weapons to deal with the new crown is the vaccine. In the future, is there still a need for a fourth injection for ordinary people who have been infected?

　　Gao Fu: In the face of the new coronavirus, breakthrough infections are very common, but vaccination can indeed work.

Therefore, whether for the elderly or the young, it is still necessary to vaccinate booster injections after natural infection.

　　However, the vaccine should not be vaccinated immediately after infection, because after natural infection, there are antibodies in the body, and immediate vaccination will neutralize the antibodies.

The purpose of vaccination is to activate antibodies, and the best interval is 3 to 6 months, because after 3 to 6 months, the antibody titers in the body will decay to a minimum.

China News Weekly: From a longer-term perspective, if the new crown becomes an endemic epidemic in the future, what is the vaccination strategy for the elderly?

　　Gao Fu: According to the current judgment, because the antibody decays to the lowest point every six months, it is equivalent to no vaccination at this time, and this virus is mainly targeted at vulnerable groups such as the elderly. Therefore, it is best for the elderly to get vaccinated every six months.

　　I appeal once again that the new crown vaccine should learn from the batch release of influenza vaccines. As long as it is the same company, the same technical route, and only changes the strain or gene sequence, there is no need to do the whole process of clinical trials, and at most only need to do I Phase clinical, and then approved for use as soon as possible.

　　Now we can't judge where the new crown virus will eventually go in the future, but for the elderly, it is likely to be the same as the flu vaccine. The flu vaccine needs to be vaccinated once a year, and the new crown vaccine must be vaccinated every six months.

For young people, when the pathogenicity of the virus continues to weaken, there is no need to keep vaccinating.

China News Weekly: As far as the treatment of the new crown is concerned, how can we reduce the medical run as much as possible?

How can antiviral drugs be used more effectively?

　　Gao Fu: Stratification, classification, and grading should be the direction of the entire medical reform.

We should take this opportunity to change our minds, put mild patients in community management as much as possible, and save more lives through such hierarchical diagnosis and treatment.

　　In addition, I would also like to call on China to contribute Chinese wisdom and Chinese solutions to the world.

At the same time, with regard to antiviral drugs and vaccines, we also need to share the achievements and wisdom of the world.

　　Antiviral drugs represented by Paxlovid and Merck's Monogravir can eliminate the new coronavirus in the early stage of use.

The use of antiviral drugs should be considered in time and space, and different treatment plans should be used for different groups of people and at different stages of disease.

When in the late stage of infection with the new crown, white lung appears, there is a large amount of exudate in the lungs, severe inflammation, and there is no virus in the body, antiviral drugs will no longer work. At this time, drugs such as tocilizumab should be used in a targeted manner.

This summer and autumn may declare the end of the pandemic

China News Weekly: The World Health Organization plans to hold a meeting on January 27 to decide whether the new crown epidemic is still a global emergency.

Previously, the WHO stated that it is expected to declare that the new crown epidemic no longer constitutes a global health emergency sometime in 2023.

From a scientific point of view, under what conditions can we end the global new crown pandemic?

　　Gao Fu: To end the COVID-19 pandemic, there are two key words, one is tolerance and the other is resilience.

We have been discussing these two terms since the beginning of the new crown epidemic.

The former refers to how much humans can bear, and the latter refers to how flexible humans are, that is, to dynamically adjust epidemic prevention measures.

When human beings can tolerate the existence of the virus, have a certain degree of resilience, live a normal life, and coexist with it, the pandemic can be declared over.

When the new crown is only prevalent in some areas, it becomes an endemic epidemic.

　　By summer or fall, it is possible that the WHO will declare the pandemic over.

But this does not mean that the death toll caused by the new crown will be as low as that of the flu, because its infection base is too large.

As for when it will be the same as the flu, it is hard to predict.

China News Weekly: You also mentioned that it is not ruled out that a new type of coronavirus will come uninvited in the future.

Based on China's anti-epidemic experience in the past three years, can you talk about what preparations we should make before or when the next pandemic arrives, so that we can respond in a more timely and effective manner?

　　Gao Fu: I advocate "One Health". Human beings should protect animals and the environment.

On this basis, it is necessary to share data and resources.

Viruses do not have passports, and viruses do not apply for visas. From the perspective of public health and the common health of mankind, it is a global game of chess.

　　In terms of specific countermeasures, early detection and routine surveillance are both very important, and at the same time, investment in related basic research must be increased.

The disease control system should rely more on professional strength and reduce administrative intervention.

It is necessary to strengthen the monitoring of relevant emergency public health events by the disease control system, such as the monitoring of respiratory-related diseases. It is necessary to strengthen the national influenza surveillance network, the national influenza sample surveillance network, the national acute respiratory infection surveillance network, and the public health emergency surveillance network. construction etc.

(China News Weekly)

　　Reporter: Du Wei Huo Siyi (huosiyi@chinanews.com.cn)