The Great Hope for the Coronavirus Vaccine in the US
Moderna’s vaccine candidate will enter Phase 3 testing next week. This phase of the trial is expected to involve tens of thousands of recipients and will determine how well the vaccine protects against developing coronavirus injection.
The vaccine is a small snippet of messenger RNA similar to that of the virus. The messenger RNA that is used to make the viral spike protein is the protein targeted by Moderna. When that messenger RNA goes into the cell, it creates and produces a protein, and when that protein is sitting on the cell, it looks just like the protein that would be sitting on a virus. The immune system recognizes this protein and starts making antibodies to different points of contact on this protein. Those antibodies that have stimulated to be be produced by the vaccine candidate will then be present to defend against the virus if the virus ever shows up with this same protein on its surface.
In phase 1 testing, side effects observed included headache, fever, malaise and myalgias. Though patients are reacting to the generation of the viral proteins. However, this is not a live virus vaccine or anything of the sort and patients are not having these reactions due to being infected. These reactions are very common to almost all vaccines, even the commonly used vaccines. Virtually all of these reactions were either mild or moderate.
The highest dose was not tolerated well, so the middle dose is the compromise of greater immunogenicity (helping to defend against the virus in the future) with lower reactivity (the side effects observed that make the vaccine unpleasant to recipients). This middle dose reached antibody levels in the high range of people infected with the coronavirus among members of the population at large.
Thus, the phase 3 trials will begin shortly to basically determine if these higher end of antibody levels are sufficient to protect against infection from the coronavirus.