Recently, Pfizer and Moderna have been approved to market a new crown mRNA vaccine, which is the first large-scale use of mRNA vaccine. There are many questions about its technology and safety, so we will discuss this new mRNA vaccine. We list 10 questions about this vaccine, we will answer them, and introduce the current situation of vaccine in China.
- What is an mRNA vaccine?
MRNA vaccine technology started in 1989, which is an artificial preparation of a sequence that can encode protein, optimized by promoter, codon, etc., and can be used as a vaccine to activate humoral and cellular immunity.
With the development of nanocarrier technology, mRNA vaccine encapsulated in nanoparticles can achieve better immune effects, improve vaccine stability, and increase immune pathways (such as intravenous injection).
- Do mRNA vaccines cause changes in the human genome?
MRNA is medium, the synthesis of protein in our bodies can also exist, mRNA to finish the work in the cytoplasm, by definition will soon been cleaned nucleic acid enzymes in the body, while the “science” reported recently living will coronavirusRNA may reverse transcription to human DNA (see below), but for the man-made mRNA will happen this kind of situation, wish to have doubts and vaccine safety were confirmed after listing, but for security verification is not guarantee for a long time, after all, is the first time.
- If lipid nanoparticles are added to mRNA vaccine as adjuvants, will these adjuvants have side effects on human body?
As a new adjuvant, lipid nanoparticles adjuvant will have its own standards for research and development and production, and safety tests will also be carried out.
Moreover, adjuvants are not only added to mRNA vaccines, but also need adjuvants to improve the immune effect of other types of vaccines, such as mineral oil adjuvants and aluminum glue adjuvants added to inactivated vaccines.
- Why is this mRNA vaccine form used in the new crown vaccine?
Vaccines come in various forms, including inactivated vaccine, attenuated vaccine, subunit vaccine, DNA vaccine, mRNA vaccine, virus carrier vaccine, etc.
Since the outbreak of the new epidemic, vaccine research has been actively carried out around the world. All the above forms of vaccines are under development and are in different stages.
The rapidity of the mRNA vaccine was partly due to the diligence of the developers and partly due to the inherent advantages of the technology.
MRNA vaccine products can be rapidly designed and optimized based on sequencing sequence and screened in animal experiments and clinical trials.
Therefore, the inherent speed advantage of “bring your own shortcut” indicates that mRNA vaccines will dominate the vaccine market in the future.
- What are the differences between mRNA new crown vaccines currently under development?
At present, the novel coronavirus spiking S protein is basically used as antigen in the development of vaccine, and there are differences only in the aspect of antigen optimization and vaccine platform.
- Research and development status of new crown vaccines in China?
The research and development of China’s new crown vaccine is based on five routes, including inactivated vaccine, attenuated influenza vector vaccine, adenovirus vaccine, nucleic acid vaccine and subunit vaccine. The three fastest inactivated vaccines have entered the end of phase III clinical practice. Recently, Sinopill China’s new biological crown inactivated vaccine has been approved for market!
- Why did the U.S. mRNA new crown vaccine go faster than China?
Different vaccine routes have different development cycles and different technical difficulties.
On the one hand, mRNA vaccine products are designed quickly and put into experimental research early.
On the other hand, due to China’s strong epidemic control efforts and good results, the lack of research samples for III clinical trials has also delayed the pace of research.
- Why don’t the West make inactivated vaccines and go the mRNA route?
The production of inactivated vaccine requires three levels of biosafety protection. In China, P3 laboratory is temporarily transformed into vaccine production, which is not done in the West. Therefore, the route of “bring your own shortcut” mRNA is not chosen for inactivated vaccine.
- Novel coronavirus consists mainly of 25-28 proteins. Why does a novel coronavirus mRNA vaccine use spiroprotein (S) alone as the target?
S protein is the key protein of virus host cell receptor-mediated virus invasion.
Secondly, S protein exists on the surface of novel coronavirus, which is a good target protein.
Finally, the premise of the selection of vaccine target protein is that the protein must be able to activate the autoimmune response. In addition to antibodies, the complete immune response also requires the co-participation of T killer cells and T helper cells.
Therefore, based on the above three points, the sequence of the vaccine targeted the spiroprotein (S).
- Which is better, inactivated vaccine or mRNA vaccine?
MRNA vaccines are mostly used in studies of cancer patients, and safety concerns in healthy people have not been completely ruled out.
In this respect, the inactivated vaccine technology is more mature.
Ultimately, a vaccine is judged by its efficacy, that is, which product protects against viral infection, with the ultimate goal of eliminating the virus.
Diversification of vaccine platforms is a good thing, as it reduces risk and improves efficiency.