The news that "Sinovac's new crown vaccine has been confirmed to be discontinued" is a hot topic of discussion in the past two days.
There are at least 3 impressions of the Sinovac vaccine:
1. The R&D and application process is relatively rapid, and it has been put into clinical use in less than a year after the new coronavirus is raging, and it has also gone through multiple links such as testing, analysis, improvement, and approval.
2. According to Sinovac's official website, by the end of 2022, the cumulative global supply exceeded 2.9 billion, making it one of the most widely used vaccines so far in the new crown epidemic.
3. A national vaccination atmosphere has been formed in China, and many Chinese people have been vaccinated with 2-3 shots of Sinovac vaccine one after another, and the scene of queuing for injection is still vivid. Some people have not been vaccinated, and the order of life has been affected.
4. Controversy persists after vaccination, with some people reporting that "pulmonary nodules" were found after receiving the Sinovac vaccine and "diabetes" was diagnosed, and at the end of 2022, at the peak of the new crown "Yiyang", the vaccine was still infected, and the effectiveness was questionable.
The key is that the current threat of the new crown virus has not disappeared, and a few days ago, authoritative media were still reminding people to strengthen their precautions, and at present, there are the latest mutant strains JN.1 abroad, which are more contagious and have more prominent escape ability, which may set off a new round of infections in China.
At the moment when a new round of new crown infections may "make a comeback", what does the suspension of Sinovac's vaccine show about the discontinuation of the vaccine? When the news came out, people who had been vaccinated and those who had not been vaccinated could not sit still.
The little doctor would like to talk about it from three aspects and talk about some personal opinions:
The first aspect: why was the Sinovac vaccine developed so quickly, and is it useful?
The "target" of the Sinovac vaccine is the early strain of the new crown, which still does not know the source and intermediate host, and belongs to an RNA virus with an extremely fast mutation rate. The development of a virus vaccine in a "smear" situation must also ensure that it is effective, and the difficulty can be imagined. However, the mainland is the first country in the world to develop a new crown clinical vaccine, leaving behind a number of drug research and development powers.
A very important reason: the new coronavirus and the SARS virus are "cousins". Although the SARS virus disappeared inexplicably a few months after the SARS virus raged in 2003, and the development of drugs and vaccines was suspended, we have preserved the basic data of the SARS vaccine.
In 2020, a similar virus appeared again, and taking out the data of the SARS virus vaccine and developing it on this basis is, of course, much faster than other medical powers.
The role of the Sinovac vaccine is not to prevent infection, and so far, no new crown vaccine can guarantee the prevention of new coronavirus infection. Its role is to prevent severe illness and buy time for medical staff to treat them. The effectiveness of the frontline health care workers is the most pertinent assessment, not the layman's evaluation.
The second aspect: will vaccination with Sinovac cause diseases such as "pulmonary nodules" and "diabetes"?
This is a particular concern for many people, and so far, no scientific research has confirmed that "vaccination causes lung nodules, diabetes and other problems".
Analysis from 4 aspects:
1. People who have not been vaccinated also have nodules. At the time of vaccination, groups with underlying diseases, advanced liver disease, pregnant women, moderate hypertension and above cannot be vaccinated, and these people also have pulmonary nodules and diabetes problems. Therefore, it is not appropriate to blame the problem on inactivated vaccines.
2. The most likely reason for pulmonary nodules is: during the new crown epidemic, a large number of medical imaging methods were used for chest scanning, and the pulmonary nodules detected appeared before the injection of vaccines.
3. The most likely reason for diabetes is that there are tens of millions of "pre-diabetic people" in the mainland, who are the "reserve army" of diabetes, and they may be in the advanced stage of diabetes during the time of vaccination. After being diagnosed with diabetes, you should look for problems such as lifestyle and eating habits.
4. There is another very important factor: Sinovac vaccine is not only used by a large number of people in China, but also exported to people in friendly countries.
The third aspect: what kind of vaccine is the Sinovac vaccine and why is it discontinued?
Sinovac vaccine is an inactivated virus vaccine, and the basic principle is: after vaccination, the immune system can recognize the "corpse" of the new crown virus and produce immune memory. It targets both the original strain and the early variants.
The main functions of inactivated vaccines are twofold:
1. Let the immune cells "remember" the appearance of the new crown strain in time, produce immune memory, and prevent the progression to severe disease.
2. Timely restrain immune cells to prevent the formation of immune storms after "killing madness", which will also endanger life.
The problem is that now that the new crown mutant strain has already mutated to the Nth generation of Omicron, the target of the inactivated vaccine may have long been "unrecognizable", which is equivalent to using a photo of the "suspect" when he was a child to deal with a suspect who has become an adult and has undergone several plastic surgery, which is unrealistic.
Therefore, there are two most likely reasons for the suspension of Sinovac vaccines: the vaccine was developed for the early stage of the new coronavirus, which has lost the ability to deal with the latest mutant strains, and the Sinovac vaccine has become a "thing of the past" with recombinant protein vaccines that are more advanced than inactivated vaccines.
The vaccine has no effect, and there are better alternatives emerging, and discontinuing the Sinovac vaccine may be the best option.
However, it cannot be denied that the Sinovac vaccine appeared at a time when the new crown epidemic was tight, and it contributed to the prevention of severe disease after being put into clinical practice, and its safety and effectiveness have been verified in early epidemic prevention.
The Sinovac vaccine has been discontinued, and we should be grateful, instead of applauding and settling accounts after the fall.