Three SARS-CoV-2 vaccines have now been fast tracked for development by the FDA. The Oxford group, CanSino Biologics and now also Moderna Pharmaceuticals have all had their experimental vaccines approved to move into Phase II trials. This means that they will begin enrolling subject participants in the coming weeks. This trial phase is designed to determine whether or not a potential vaccine can cause a person’s immune system to produce antibodies that recognize the virus.
At present, the vaccine farthest along in development is the one being developed by Oxford University’s Jenner Institute. Jenner had already developed human trial safety information from trials of similar vaccines for the MERS virus, also a coronavirus. The Oxford-Jenner SARS-CoV-2 vaccine is now entering a study involving 6,000 people. This vaccine is based on a procedure that involves genetically modifying a harmless virus to create at SARS-CoV-2 duplicate that doesn’t cause disease but does teach the immune system to react to the dangerous virus.
Moderna’s vaccine works differently. It is made out of messenger RNA, which explains the mRNA in the vaccine’s name. This molecule carries the genetic recipes for different proteins to a cell’s protein production area. The cell is then triggered to make a tiny amount of the protein that SARS-CoV-2 uses to infect human beings. In turn, this trains the body’s immune system to recognize the virus and attack it the next time it shows up.
This is a new type of vaccine that has never been used in humans before, but the initial safety trial carried out in March convinced the FDA to give the company a green light for further testing.
Other promising trials are also under way. On Monday, 15 volunteers in New York (all healthy) received initial doses of an mRNA-based vaccine similar to Moderna’s, called BNT162. Pfizer and the German company BioNTech, are jointly producing BNT162. Over the next few weeks, the Phase I trial will enroll 360 people in an initial safety trial.
While all trial volunteers will be monitored for 2 years, since most bad reactions happen early, it is hoped that enough data can be gathered over the next three or four months to determine if the vaccines are safe.
Given the urgency of the situation and the speed of these trials, it is possible that one or more vaccines could be available by the end of 2020, or in the 1st quarter of 2021.