How do COVID-19 vaccines work?
Vaccines work by mimicking an infectious agent — viruses, bacteria, or other microorganisms that can cause disease. This simulation ‘teach’ our immune system to respond quickly and effectively against the infectious agent.
Vaccines have traditionally done this by delivering a weakened form of the infectious agent that allows our immune system to build a memory to deal with. In this way, the immune system can quickly identify the infectious agent and fight it before it makes us sick. This is how some COVID-19 vaccines are designed.