August 8, 2022

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mRNA or inactivated vaccine: what is the best  to defeat COVID-19?

mRNA or inactivated vaccine: what is the best  to defeat COVID-19?



mRNA or inactivated vaccine: what is the best  to defeat COVID-19?    At present, among the vaccines used to prevent new coronavirus infection in the world, the most introduced and noted varieties are mainly inactivated C0VID-19 vaccines and mRNA COVID-19 vaccines.




Inactivated vaccine

Inactivated vaccines originated in the 15th century AD when Portuguese sailors in Africa were invented toxoids by local indigenous people using ant nests to treat snake venom.

Later, on the basis of toxoids, people used formalin and other chemical agents to kill pathogens, causing them to lose their pathogenicity and infectious ability, but retain the immunogenicity, which became the inactivated vaccines we use now.

Inactivated vaccines have a long history, but the preparation is simple, the research cost is low, and the effect is stable. This simple and rude characteristic.

Inactivated vaccines are the easiest vaccine species for humans to develop successfully, because as long as the pathogen can be successfully isolated or cultured, and then inactivated, the inactivated vaccine has already been half successful.

For more than 100 years, humans have invented and used many kinds of inactivated vaccines and toxoids, including pertussis vaccine, hepatitis A vaccine, influenza vaccine, diphtheria toxoid and tetanus toxoid and so on.

People have very rich experience in the production and application of inactivated vaccines, the production process is the most mature, and the composition of the vaccine is the most stable, so it has very good safety and effectiveness. Because of this, many other types of vaccines are gradually being replaced by inactivated vaccines. For example, live attenuated polio vaccine (OPV) has been gradually replaced by inactivated polio vaccine (IPV), while humans use rabies. Live attenuated vaccines have also been replaced by inactivated vaccines.

In the face of new pathogens, humans often think of inactivated vaccines first, because they have the characteristics of rapid development, convenient production, convenient use, safety, reliability and stability. The most classic example is the flu vaccine.

Because the flu virus mutates very fast, new strains may appear every year, so the strains of the flu vaccine are different every year. Under this circumstance, a corresponding flu vaccine must be produced for each new strain. This is an opportunity for inactivated vaccines to show their talents. Therefore, inactivated vaccines currently used in China are the most used varieties.

mRNA or inactivated vaccine: what is the best  to defeat COVID-19? 





mRNA vaccine

In this COVID-19epidemic, a vaccine variety that integrates the world’s top biotechnology-mRNA vaccine has also emerged.

This vaccine uses bioinformatics analysis to obtain the amino acid sequence of the protective epitope in the spike protein of the new coronavirus, and then obtains the encoded mRNA sequence through reverse biology technology. After base modification and transformation, an mRNA vaccine is synthesized. Then use modern chemical technology to synthesize nano-liposome carrier and package the mRNA to obtain the finished vaccine. In use, you only need to inject the mRNA vaccine into the human body, and the nanoliposome carrier will bring the vaccine mRNA into the normal tissue cells of the human body (such as muscle cells). The vaccine mRNA can use the protein translation system in these cells to transfer The epitope of the new coronavirus spike protein is expressed on the tissue cell membrane for the body’s immune system to recognize and produce immune response effect products such as antibodies to play a protective immune effect against new coronavirus infection.

Before the emergence of the COVID-19 virus infection, mRNA vaccines were synonymous with tall biological products. The price of a dose was hundreds of dollars, and the preparation, storage and transportation conditions were particularly harsh, requiring a deep low temperature of -80 degrees Celsius. Only in the “decapitation action” used to treat malignant tumors can mRNA vaccines be sent to battle. In the prevention and control of infectious diseases caused by pathogen infection, there is no experience and precedent for the development, production and use of mRNA vaccines.

At present, in the battle against the COVID-19 virus, Sinopharm and Kexing represent inactivated vaccines. The vaccine production process is mature, safe, and has good stability. It has low requirements for storage and transportation conditions. It only requires ordinary cold chain transportation. It has been widely used in third world countries such as Brazil, Pakistan and the United Arab Emirates. Recognized and widely used.

The mRNA vaccines produced by Moderna and Pfizer in the United States have also won the favor of European and American countries because of the excellent protection rate data obtained in clinical trials. In particular, 72% of the population has been vaccinated in Israel. However, mRNA vaccine is a new type of vaccine, and the production process and production materials are not mature enough. Some raw materials, such as PEG (polyethylene glycol), are not approved vaccine production materials. Vaccine-related safety incidents such as allergic reactions are also occasional. Report. There are also reports that the incidence of side effects of the COVID-19 vaccine in European and American countries is as high as 80%.

Although the adverse reaction rate of mRNA vaccines is generally within the acceptable range of people, compared with them, China’s inactivated vaccines are more safe and have better applicability. Therefore, many countries are more optimistic about China’s inactivated vaccines.

mRNA or inactivated vaccine: what is the best  to defeat COVID-19?


However, the war between humans and the COVID-19 virus may be a protracted war. Human vaccine weapons have just appeared on the scene, and there are still many unanswered questions. For example, how long can the protective immunity caused by the vaccine last? How long do we need to get a vaccine to maintain continuous protective immunity against the new coronavirus? and many more. Moreover, in large-scale application, can the effective protection rate of the vaccine still maintain its good results in clinical trials? This also requires practical applications to test!

In short, our battle against the COVID-19 virus has just begun, and it is still unknown who will be the final winner! However, humans will eventually defeat the new coronavirus. This outcome is certain, because whether it is an inactivated vaccine or an mRNA vaccine, as long as it is a weapon, humans will find scientific methods of use, or continue to improve and perfect them, and do them well. Good upgrade, good use! The ultimate winner must be us, humans!

(source:internet, reference only)

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