Cell: China has developed a new mRNA new coronapneumonia vaccine, which can maintain thermal stability in vitro for at least a week.

July 27, 2020 /prNewswire --- In a new study, researchers from the Chinese Academy of Military Medical Sciences, Suzhou Aibo Biotech Co., Ltd., the China Food and Drug Research Institute, Tsinghua University and the Institute of Life Almanology of the Institute of Military Medicine reported that an experimental SARS-CoV-2 vaccine based on messenger RNA (mRNA) can cause protective immune responses in non-human primates.two injections of this vaccine are strong enough to produce a strong immunity and completely prevent sars-CoV-2 infection in mice.related findings were published online July 23, 2020 in the journal Cell, under the title "A thermostable mRNA vaccine against COVID-19".the paper's correspondent sits with Dr. Cheng-Feng Qin of the Chinese Academy of Military Medical Sciences, Dr. You-Chun Wang of the China Food and Drug Inspection Research Institute and Dr. Bo Ying of Suzhou Aibo Biotech Co., Ltd.images from Cell, 2020, doi: 10.1016/j.cell.2020.07.024. "The strong protective effects observed in this study and the clear immune correlation seisassociated with this protective effect pave the way for future development of the COVID-19 vaccine in humans," said Dr.Qin Chengfeng."MRNA-based vaccines are an attractive option to prevent SARS-CoV-2 infection because they can be designed and mass produced quickly and on a large scale in a matter of weeks."In addition, preclinical studies have shown that mRNA-based vaccines can induce a strong and broad protective immune response to a variety of pathogens and have acceptable safety.in the new study, the researchers developed a vaccine consisting of mRNA, which encodes the receptor binding domain (RBD) of the stingprotein (S) on the surface of SARS-CoV-2.the vaccine, known as ARCoV, is encapsulated in lipid nanoparticles, which improves its delivery to tissues.targeting RBD instead of the entire S protein may represent a safer option and may trigger fewer non-neutral antibody production.these non-neutral antibodies may enhance the virus into cell and viral replication through a process called antibody-dependent infection enhancement (antibody-dependent enhancement of infection, ADE).ADE has previously been reported in SARS-CoV viruses that are related to SARS-CoV-2, of which SARS-CoV was the pathogen that caused the OUTBREAK of SARS from 2002 to 2003.the researchers injected ARCoV into the muscle tissue of 16 mice and gave a booster injection two weeks later.the vaccine causes high levels of neutralizing antibodies that protect them by preventing SARS-CoV-2 from interacting with host cells.these neutralized antibodies are cross-reactive and provide broad protection against three different SARS-CoV-2 strains.in addition, the vaccine increases the number of T cells in the spleen. mice injected with two doses of ARCoV were exposed to SARS-CoV-2 after 35 days, with no signs of viral RNA in their lungs or trachea, and no lung damage or inflammation. results from 20 crab-eating monkeys showthat two doses of ARCoV induce viral-specific T-cell reactions and neutralizing the production of antibodies, and produce levels of neutralizing antibodies far higher than most recovered PATIENTs with COVID-19. , none of the animals vaccinated against the vaccine had adverse reactions. to assess the thermal stability of ARCoV, the researchers stored the vaccine at different temperatures for 1, 4 or 7 days, then injected it into mice and visually observed its distribution in mouse tissue. results showed that after a week of storage at room temperature, the vaccine achieved the same high level of expression after being effectively delivered to the tissue, with no signs of reduced activity. "A ready-to-use thermal stability vaccine like ARCoV is ideal and eliminates the need for cold-chain transportation, " said Dr. Qin Chengfeng. ", "These researchers are currently evaluating the long-term stability of ARCoV. "Furthermore, the duration of ARCoV-induced neutralizing antibodies has yet to be determined, as experience from other human coronaviruses suggests that reinfection is possible due to the weakening of the antibody response," said Dr. Qin Chengfeng. future research needs to assess the long-term immune response of animal models and the effectiveness of ARCoV in the human body. " (bioon.com) References: 1.Na-Na Zhang et al. A thermorna mRNA vaccine against COVID-19. Cell, 2020, doi: 10.1016/j.cell.2020.07.024.2.Tharna-based-vaccine candidate sos animals against SARS-CoV-2.