[ad_1]
Original title: The cause of positive environmental nucleic acid inoculation has been found! The virus is obviously dead, why can it show the sun?
Source: Zhang Jiaxing, Science and Technology Daily
Recently, some provinces tested positive for the nucleic acid of the new coronavirus in environmental samples collected and analyzed by the new coronavirus vaccination unit.
Xianyang means “red light” during the investigation of infected people and the environment, suggesting that there may be a new coronavirus here.
So does the “red light” around the vaccine this time mean there is a virus “resurfacing”? Will it bring infection?
To this end, the China Center for Disease Control and Prevention conducted further research and analysis of vaccine samples and solutions, and issued the “Technical Recommendations on Monitoring Environmental Samples from New Coronary Vaccination Units” (called ” Recommendations “) on January 24. The positive cause is the dead strain in the vaccine solution.
So the question is, the virus is dead, why can it show the sun? How can you prove that he really died?
web page screenshot
How he died
To prove that the virus is dead, you must first find out how it died.
The new corona vaccine that is currently being vaccinated is an inactivated vaccine. As its name implies, it “kills” the virus.
Killing viruses is not using a “knife and gun” in the macroscopic world, but using chemical methods to inactivate vital virus molecules.
For example, β-Propiolactone does not act directly on the protein, but it can target the virus and destroy its nucleic acid. It’s like drinking arsenic for the virus and dying from “intestinal puncture.”
For another example, formaldehyde can destroy amino-containing nucleotide bases (such as A, G, U) in viral nucleic acid, as well as the coat protein of the virus. This is like pouring sulfuric acid on the virus and “burning both body and mind. And dying.”
“There are many types of virus inactivating agents.” Yang Xiaoming, chairman of Sinopharm Group, Zhongsheng Biological, mentioned above in Science and Technology Daily science and technology reporter popular science reporters, inactivated vaccines. 4. Research on the inactivating effects of five different inactivators. Inactivation cannot be enough. If there are live viruses, it will cause infection and cannot be “overloaded.” If inactivation destroys all antigens on the surface of the virus, the effectiveness of the vaccine is poor.
Inactivation is like “cutting the weeds and the roots of the tofu”, you cannot crush the tofu but also eradicate the grass.
Regarding whether it is “dead” and whether it is still effective, the researchers did a lot of experimental verification work during research and development, exploring the optimal type of inactivating agent and the control of inactivation time, temperature, dose and other parameters.produce.
Really died
After production and before the vaccine reaches the mentioned vaccination unit, it is necessary to inspect it, a basic requirement for qualification is to verify that the virus is indeed dead.
my country implements a strict system for issuing lots of vaccines. On December 31, the joint prevention and control mechanism of the State Council held a press conference. Chen Shifei, deputy director of the State Administration of Medicines, said that every batch of new coronavirus vaccines that leaves the factory will be issued by the medicine regulatory authority. At present, the Beijing and Hubei Province drug inspection and regulation agencies have been awarded the batch issuance of the new corona vaccine.
In other words, every vaccine that enters the vaccination process has undergone strict data review and laboratory testing for the same batch of vaccines.
On December 25, 2020, staff inspected product packaging quality at the new coronavirus-inactivated vaccine sub-packaging workshop of Beijing Institute of Biological Products of Sinopharm Group. Xinhua News Agency reporter Zhang Yuwei
A document on “Key Points of the Virus Inactivated Vaccine Production Process” written by researchers from the Drug Evaluation Center of the National Administration of Medical Products showed the strict requirements for virus inactivation tests: detailed information is required on the Verification of virus inactivation, usable Sensitive cells are passed blind for 3 generations, each generation of cells is analyzed and the most sensitive detection method is used to verify that there is no live virus. The method must have sufficient sensitivity and repeatability. Double samples must be taken at each sampling point …
In summary, the inactivated vaccine must be verified by a repeatable double sample and ensure that the third generation is not alive. Some verifications must be supported by animal testing and other multi-angle and multi-level testing. The virus in the inactivated vaccine is really dead.
As long as it “matches”, it can show the sun
So, since the virus in the inactivated vaccine is completely dead, why is the detection of nucleic acid from environmental samples still “red light”?
The nucleic acid detection principle can be imagined as two small worms biting the willow leaves on both sides. As long as the willow leaves are “tasty”, the little worms will walk back and forth on both sides of the willow leaves, copying the same willow leaf border pattern each time they move The same nucleic acid .
“Pleasant to taste” is the key. As long as the “bumps” of the “little bug” and the “bumps” on the edge of the willow leaf can coincide, it can play the role of “primer” to guide the PCR reaction. Many of the same sequences were amplified from the nucleic acid sequence of “”, and positive results were revealed.
If the primer cannot find a “match” sequence and cannot amplify, it will be negative.
In the process of inactivating the vaccine, the virus is completely killed, but the “face” of the nucleic acid may not be completely destroyed. To use an inappropriate analogy, facial recognition of a dead person is likely to be successful.
In this regard, the Chinese Center for Disease Control and Prevention stated in the above “Recommendations” that it is not recommended to routinely collect environmental samples and nucleic acid tests for inoculation units. If surveillance has been conducted and found to be positive, or the viral nucleic acid test from environmental samples collected near the vaccination site is positive, it is recommended to use the virus genome sequencing method to determine if the acid nucleic is a vaccine. Pressure. That’s using a more comprehensive sequencing method to further verify if the “red light” is a true alarm.
Massive information, accurate interpretation, all in the Sina Finance APP
Editor in Charge: Xue Yongwei
