Pharmaceutical companies might have there been other mrna vaccines and strategies to deal with covid-19

A new Singapore study comparing the effectiveness of the Covid-19 vaccine against COVID-19 virus infection and severe disease prevention was published in Clin Infect Dis on April 12, 2022. The study compared available vaccines in Singapore. Pharmaceutical companies in Singapore have there been other mrna vaccines, and the investigation found that mRNA vaccines have higher efficacy than non-mRNA vaccines.

There are currently several COVID-19 vaccines in development in China. The COVID-19 vaccines currently under development in China are mainly focused on the three technical pathways of mRNA, recombinant protein and viral vector. With the advancement of COVID-19 vaccine research, China will have a richer variety of COVID-19 vaccines in the future, which will provide more options for subsequent COVID-19 vaccine sequential booster vaccination. For the current vaccine market, relevant departments also have there been other mrna vaccines.

mRNA vaccines

The process of mRNA vaccine development involves the selection of an antigenic protein specific to the target pathogen, sequencing, synthesis and cloning of the protein gene into a DNA template plasmid, in vitro transcription into mRNA, and inoculation into the subject. Compared with traditional vaccines, mRNA vaccines have similar immune response mechanisms as live viruses, no risk of infection or integration into the host genome, more stable and efficient expression of antigenic proteins, and simple and rapid chemical synthesis for cost reduction and mass production. Currently, self-amplifying RNA is the most studied type because it contains an α-viral genome with a complete set of relevant genes encoding the RNA replication machinery. During the COVID-19 pandemic, the potential of mRNA vaccine platforms to respond to infectious disease outbreaks caused by new pathogens was greatly exploited. The clinical trial data of BNT162b2 developed by BioNtech and BioNTech, mRA-1273 developed by Moderna and NIH, and ARCoV developed by Watson Biosciences, Abbott Biosciences, and the Academy of Military Medical Sciences have shown good safety, tolerability, and protective efficacy. protection. In addition, mRNA vaccines have been used in the development of herpes zoster vaccines, Zika virus vaccines, and influenza vaccines with good results.

Viral vector vaccines

Viral vector vaccines have the advantage of being safe, having a wide host range, wide application, and a wide variety of dosage forms. A viral vector vaccine is a vaccine that uses an attenuated strain of viral vaccine or a non-replicating virus as a vector to efficiently deliver the antigenic gene code to the host cell nucleus and trigger an immune response. Various viruses, such as adenovirus, lentivirus, herpes stomatitis virus, herpesvirus, measles virus and recombinant cowpox virus Ankara strain, have been used as vectors for vaccine development. Viral genomes can express any specific antigen and can stably accept large gene fragments for insertion, and antigens can be accurately synthesized, modified, and targeted to specific cells in the host, allowing viral vector technology to be used for a variety of vaccine developments. Viral vectors induce a strong humoral and cellular immune response in target cells similar to the natural infection process. The main viral vector vaccines that have been marketed and approved for use are the adenoviral vector Ebola vaccine and the COVID-19 vaccine. Viral vector vaccines have the advantages of safety, broad host range, wide application, and a wide variety of dosage forms, but have certain shortcomings in terms of targeting, duration of expression, and the immune response induced by the vector itself.

Inactivated vaccines

Inactivated vaccine technology is relatively mature and has a high safety profile. Inactivated vaccines are a class of vaccines in which viruses or bacteria are cultured and then inactivated by physical or chemical treatment to obtain no infectious activity. Compared with attenuated vaccines and genetically engineered vaccines, inactivated vaccines have the advantages of short development cycle, relatively mature preparation process, non-infectious virulence and high safety. However, they generally require multiple vaccinations to produce protective immunity and usually induce a humoral immune response, while cellular immunity is generally weak. Inactivated vaccines currently available in China include inactivated polio vaccine, inactivated BSE vaccine, diphtheria-tetanus (Pertussis) vaccine, influenza vaccine and human rabies vaccine. Inactivated vaccine platforms are relatively mature, with high safety and fast response time to new pathogens.

Dr. Zhao Xiaobin, a former FDA senior reviewer, said that mRNA vaccines with short production cycle, low R&D cost and standardized production are likely to be the "ultimate solution" for future outbreaks, and China really needs independent and controllable mRNA vaccines to deal with the covid-19 epidemic.