Did you know that for more than a DECADE, scientists have been working on the new technology utilized in this vaccine? They started working on it as a vaccine for SARS, another corona-virus. They have been perfecting the technology for an mRNA vaccine. Now they have achieved it. This work did not start with the appearance of COVID-19 and has been in the works for years.
Vaccines 101: A typical vaccine utilizes a piece of the virus or an "attenuated" or non- infectious virus to trick the body into mounting an immune response and create ant-bodies.
mRNA vaccines are entirely different. They do not utilize any part of the virus at all. Think of mRNA as pieces of computer code that your body can read. They have created a piece of code(mRNA) that tricks the body into creating the spike protein that COVID uses to attach to its host and cause infection. It only creates the spike, which is harmless. The body then mounts an immune response against this "spike", which the body recognizes as foreign, and makes anti-bodies against the spike. Now, when the actual Sars-Cov2 virus is introduced into the host, the anti-bodies against the "spikes" will now render the virus harmless.