第一針

上臂麻痺，肩頸酸痛

Image: nationalgeographic.com

The vaccine contains small pieces of viral messenger RNA, a molecule with instructions for making proteins. Scientists pack the mRNA inside a slippery pod made of lipids, so it can slide into the cells.

Once inside the cells, the mRNA finds ribosomes. A ribosome is a cellular particle made of RNA and protein that serves as the site for protein synthesis in the cell. The ribosome reads the sequence of the mRNA and, using the genetic code, translates the sequence of RNA bases into a sequence of amino acids.

Ribosomes start making SARS-CoV-2 spike proteins based on the viral mRNA. Spike proteins coat the surface of the virus and are harmless on their own. They are considered a good vaccine target which is also called an antigen.

An immune cell perceives the spike proteins as if the body had been infected. It kicks off a sequence of events that result in the creation of antibodies and other defences.