Mar 16, 2021 05:19 AM

Zhang Wenhong: How to View Adverse Vaccination Reactions

Zhang Wenhong
Zhang Wenhong

As many major countries in the world push forward with vaccinations, the time for the world to open up is getting closer and closer. I believe that China will be able to approach Covid-19 vaccination rationally, ultimately achieving herd immunity and finally overcoming this pandemic.

Which vaccine is better? The reality is, there may be different data on the efficacy of different vaccines for preventing Covid-19. Studies done in different countries can put the efficacy of the same inactivated-virus vaccine at different levels. However, there is one statistic that we are all close to. For the several vaccines that are used more internationally — the mRNA vaccine, adenovirus vector vaccine, and inactivated-virus vaccine — the efficacy for preventing severe Covid-19 cases is above 95%, nearing 100%. Therefore, one of the most significant effects of vaccination is preventing infection as well as high-risk events after infection.

Of course, other vaccine lines are being developed in China. I believe that with continuous communication of experts worldwide and universal availability of vaccines, the problem of the epidemic will eventually be solved through united action.

It should be said that eventually all these vaccines will be widely used worldwide. However, in the process of global vaccination, some occasional adverse reactions may unavoidably occur.

Before the Covid-19 pandemic, vaccines in China have mainly been given to children, and almost every child in China receives many kinds of vaccinations. This is in contrast to other countries, where overall acceptance of vaccines is relatively high and many adult vaccines are also given in large quantities, such as the HPV vaccine, the influenza vaccine and other adult vaccinations that are more widely available abroad. Flu vaccination in China, as far as I know, is only about 3%.

In other words, the overall vaccination rate is still unbalanced at the international level. Without making too many comparisons, we can say that there is not a habit of vaccination in China, which has led to heightened concern about adverse reactions to vaccines. In reality, there are some occasional adverse reactions, but we need to investigate scientifically before concluding that these events are necessarily related to vaccination.

Right now, there are three primary concerns about vaccination. First, is vaccination useful or not? People think that we don't have active cases in China now, so why get vaccinated? Second, is the vaccination safe? Third, what is the efficacy rate?

Many health experts say vaccines are safe for the general population, but as the vaccine is an exogenous biological product, abnormal reactions may indeed occur after it enters the human body due to individual differences. These reactions include general abnormal reactions, more serious abnormal reactions, and even life-threatening reactions, such as anaphylaxis. It is possible for some people to have an allergic reaction to the vaccine, but the country is working on all fronts to ensure and improve the production process of vaccines to reduce abnormal reactions. Therefore, it is suggested that when encountering such adverse symptoms, we should go to the hospital or communicate with medical professionals in a timely manner instead of attributing these coupled reactions to the vaccine and losing confidence in vaccination.

There are many people who say they don't want to be vaccinated because China’s epidemic is under control, believing that the problem can be solved by testing people coming from outside our borders. As China is now the second-largest economy in the world with frequent international exchanges, shutting our borders while developed countries remain open to each other will cause major problems. Of course, China can also choose to open our borders to foreign countries without implementing Covid-19 testing and still quarantine foreign arrivals for two to four weeks. However, this would still have an extremely detrimental impact on both China's international image and the economy, making it difficult to achieve the 14th Five-Year Plan GDP growth proposed by the National People's Congress. People’s wellbeing ultimately depends on economic development as well as the prevention and control of diseases.

Professor Zhong Nanshan told an international conference last week that China has plans to reach a 40% vaccination coverage rate by June. So at this stage I hope we can learn more about the international and domestic situation of adult vaccination. Vaccination is an inevitable choice if we really want to achieve a joint victory by China and the world against the coronavirus. If we don't meet the 40% expectation in the first half of this year, we will have to accomplish the goal in the second half of the year. If we don't meet it in the second half of the year, then eventually we will have to set the goal for next year.

I’ve always believed that in addition to the current inactivated viral vector vaccine, other lines of vaccines from China, including some vaccines resulting from international cooperation, will continue to develop. Within two years, it will be possible to gradually achieve better vaccination on an international scale, so I have strong confidence in the future.

I hope everyone can come to understand more about the vaccination of adults and the future vaccination of children, especially regarding the Covid-19 vaccine. I hope we can build up confidence for voluntary vaccination by reaching a public consensus instead of enforcing compulsory vaccination. China should always insist on voluntary vaccination, and I believe that we will be able to accomplish the wonderful goal of achieving universal mass immunization through it.

In addition, I have one more cause of hope in mind. As of now, we have not found the main host of the new coronavirus in nature, so it is possible that it exists in bats, just like SARS in 2003. As bats rarely appear among humans, as long as we can cut off our close relationship with wild animals, especially through stopping the environmentally destructive habit of eating wild animals, we might be able to eliminate Covid-19 as we did smallpox through universal vaccination and public health policies.

This is not to deny the difficulty of complete virus elimination. Yu Hongjie, professor at the School of Public Health at Fudan University, ruled out the possibility based on the fact that the Covid-19 has already met the conditions for being a resident virus in humans. Still, I am hopeful that we will be able to control the coronavirus pandemic differently from the way we handle the flu.

How this pandemic ends will, of course, be answered in the future. Though our biggest challenge in preventing and controlling various diseases today is the uncertainty of the future, as a human race, we have a very good habit: We are always able to face reality. This ability is the reason why human society has flourished globally in the 65,000 years since Homo sapiens came out of Africa. In these 65,000 years, we have experienced countless disasters, but never has the human race become extinct. I believe that this time, mankind will still be able to overcome this virus through our trust in science and the ultimate rationality of mankind.

Zhang Wenhong is director of the infectious diseases department at Huashan Hospital in Shanghai.

This article was compiled by Caixin reporters from Zhang Wenhong's March 14 speech at the "Vaccination for All" multidisciplinary forum on vaccines.

Translated by intern reporter Lin Ting.

The views and opinions expressed in this opinion section are those of the authors and do not necessarily reflect the editorial positions of Caixin Media.

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