A clinical stage biotechnology company pioneering messenger RNA (mRNA) therapeutics and vaccines to create a new generation of transformative medicines for patients, recently announced positive interim clinical data of mRNA-1273, its vaccine candidate against novel coronavirus (SARS-CoV-2), from the Phase 1 study led by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH).
I. Virus vaccines:
At least seven teams are developing vaccines using the virus itself, in a weakened or inactivated form. Many existing vaccines are made in this way, such as those against measles and polio, but they require extensive safety testing.
Sinovac Biotech in Beijing has started to test an inactivated version of SARS-CoV-2 in humans.
II. Viral-vector vaccines:
Around 25 groups say they are working on viral-vector vaccines. A virus such as measles or adenovirus is genetically engineered so that it can produce coronavirus proteins in the body.
These viruses are weakened so they cannot cause disease. There are two types: those that can still replicate within cells and those that cannot because key genes have been disabled.
III. Nucleic-acid vaccines: ( example: mRNA1273 ) At least 20 teams are aiming to use genetic instructions (in the form of DNA or RNA) for a coronavirus protein that prompts an immune response. The nucleic acid is inserted into human cells, which then churn out copies of the virus protein; most of these vaccines encode the virus’s spike protein.
IV. Protein-based vaccines:
Many researchers want to inject coronavirus proteins directly into the body. Fragments of proteins or protein shells that mimic the coronavirus’s outer coat can also be used.
Industry trials:
More than 70% of the groups leading vaccine research efforts are from industrial or private firms. Clinical trials start with small safety studies in animals and people, followed by much larger trials to determine whether a vaccine generates an immune response. Researchers are accelerating these steps and hope to have a vaccine ready in 18 months.
1 of 3 : what is moderna's mRNA-1273?
2 of 3: modalities ( method of therapeutic approach ) explained
3 of 3 : understanding the race for the covid-19 vaccine
Source: Fig. 2 in T. Thanh Le et al. Nature Rev. Drug. Disc. http://doi.org/ggrnbr (2020). Callaway, Ewen. “The Race for Coronavirus Vaccines: a Graphical Guide.” Nature News, Nature Publishing Group, 28 Apr. 2020, www.nature.com/articles/d41586-020-01221-y?utm_source=Nature+Briefing&utm_campaign=8952c41133-briefingdy-20200428_COPY_01&utm_medium=email&utm_term=0_c9dfd39373-8952c41133-44584153.