Two NEJM papers show that the experimental new crown vaccine mRNA-1273 has broad prospects.

!--:page:--2 ---9 (UPI) -- In a new study, researchers from the National Institutes of Allergy and Infectious Diseases (NIAID) affiliated with the National Institutes of Health (NIH) reported that two experimental vaccines to prevent 2019 coronavirus disease (COVID-19) induce a powerful immune response and quickly control the respiratory tract in the respiratory monkeys exposed to CO-Co-SARSV-2.
related findings were published online July 28, 2020 in the journal NEJM with the title "Evaluation of the mRNA-1273 Vaccine against SARS-CoV-2 in Nonhuman Primates".
picture from CC0 Public Domain.
the vaccine, called mRNA-1273, was developed by scientists at the NIAID Vaccine Research Center and Moderna, a company based in Cambridge, Massachusetts.
the results of this animal study complement the preliminary results of the recently reported phase 1 clinical trial using mRNA-1273 sponsored by NIAID.
the candidate vaccine is produced by Moderna.
in the study, three groups of rhesus monkeys (8 in each group) received two injections of 10 or 100 mRNA-1273 or a placebo. The
injection interval is 28 days.
vaccinated rhesus monkeys produce high levels of neutralizing antibodies, producing neutralizing antibodies that target SARS-CoV-2 to attach to and enter the cell's surface protrusion protein.
the researchers, it is worth noting that rhesus monkeys receiving a 10?g or 100-g dose of candidate vaccine produce significantly higher levels of neutralizing antibodies in their blood than those of COVID-19 recovery.
this experimental vaccine can also induce th1 T cell reactions, but not Th2 T cells.
induced induction of Th2 responses is associated with a phenomenon called vaccine-associated respiratory disease enhancement (associated with the disease, VAERD).
vaccine-induced Th1 response was not associated with VAERD of other respiratory diseases.
in addition, this experimental vaccine-induced bubble-assisted T-cell response may contribute to the production of powerful antibody reactions.
four weeks after the second experimental vaccine was injected, all rhesus monkeys were exposed to SARS-CoV-2 through their noses and lungs.
noteworthy, two days after exposure to the virus, seven of the eight rhesus monkeys vaccinated in two groups did not detect a replication virus, while all eight placebo-injected rhesus still had a replication virus in their lungs.
, in addition, in the eight rhesus monkeys that were vaccinated with the 100-m RNA-1273 vaccine, none of them detected the virus in their noses two days after it was exposed.
the researchers point out that this is the first time that an experimental COVID-19 vaccine tested in non-human primates can produce such rapid virus control in the upper respiratory tract.
added that a COVID-19 vaccine that reduces the virus's replication in the lungs will limit the disease in individuals, and reducing the loss of the upper respiratory tract will likely reduce the spread of SARS-CoV-2, thereby reducing the spread of the disease.
previously, the mRNA-1273 research team has conducted a phase 1 clinical trial in humans using the experimental vaccine mRNA-1273, the preliminary results of which were published online July 14, 2020 in the journal NEJM, with the title "An mRNA Vaccines SARS-CoV-2 - High Report".
the phase 1 clinical trial recruited 45 participants between the ages of 18 and 55 in three groups of 15 people.
the team gave the three groups two doses of 25, 100 or 250 micrograms of the vaccine, each with a 28-day interval.
all participants received the first dose of the vaccine, but only 42 received the second dose.
there were no reports of serious adverse events in terms of security.
more than half of the participants reported fatigue, headache, chills, myalgia, or pain at the injection site.
systemic adverse events are more common in people who are vaccinated for the second time and receive the highest dose of the vaccine.
data on side effects and immune responses in various vaccine doses provides a basis for the use or planned use of doses in Phase 2 and 3 clinical trials of this experimental vaccine.
the Phase 1 clinical trial measured the level of neutralizing antibody activity induced by the vaccine on the 43rd day after the second dose of the vaccine was injected.
two doses of vaccination promoted high levels of neutralizing antibody activity, and their activity was higher than the average seen in the recovery period serum obtained from confirmed PATIENTs WITH COVID-19.
these two studies provide a solid foundation for the development of Phase 2 and Phase 3 clinical trials using mRNA-1273.
Phase 2 clinical trial of the vaccine began registering at the end of May.
Phase 3 efficacy trial for the vaccine is scheduled to start in July 2020.
(bioon.com) References: 1.Kizzmekia S. Corbett et al. Evaluation of the mRNA-1273 Vaccine against SARS-CoV-2 in Nonhuman Primates. NEJM, 2020, doi:10.1056/NEJMoa2024671. 2.Eith COVID-19 Vaccine sups upper and lower airways yn nonhuman primates title """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" An mRNA Vaccine against SARS-CoV-2 - Preliminary Report. NEJM, 2020, doi: 10.1056/NEJMoa2022483. 4. Xei COVID-19 vaccine, generates immune response.