Messenger RNA (mRNA) vaccines

An mRNA vaccine doesn't use the germ itself. Instead, it tells your cells to make a harmless piece of the germ based on an mRNA blueprint, which causes your immune system to respond. The cells can only make the piece of the germ for a short while, while the mRNA is still present. The mRNA does not become part of your cells, and your body does not continue to make the protein long term.

Currently, mRNA vaccines are used to protect against COVID-19. Scientists are developing other vaccines of this type, including new kinds of flu shots.