The public needs to know that the vaccines from Pfizer, Moderna and AstraZeneca are something entirely new: they are mRNA (messenger RNA) vaccines.

What is messenger RNA? mRNA is like a blueprint that tells a cell how to make a specific protein.

Why is this important? Traditional vaccines use dead or inactivated virus injected into a person, or they use a protein which has been isolated from the virus injected into a person, causing the immune system to form antibodies against the virus.

mRNA vaccines do not use a virus or a viral protein. Instead, they use a piece of laboratory-created messenger RNA, essentially a man-made synthetic copy of part of Covid-19's mRNA.

The mRNA vaccines "trick" the body's cells into making Covid-19's spike protein. The body then recognizes the spike protein as foreign, and makes antibodies against it. The mRNA vaccine may also stimulate other portions of our immune system (the innate immune system or the T cell immune system) in addition to the production of antibodies, potentially making them more effective than traditional vaccines.

mRNA vaccines are revolutionary because they let the recipient of the vaccine do the work of producing the viral protein that triggers the immune response. Time to develop such a vaccine, and cost to produce the vaccine, are significantly reduced.

There are unknowns: the true efficacy when given on a large scale, and the potential for undesirable side-effects. The Covid vaccines will be the first time mRNA vaccines have been approved for use. The population should understand that they are participating in something entirely new. Quite fitting for 2020.