By Mayo Clinic Staff
COVID-19 vaccines cause the immune system to make antibodies to fight the COVID-19 virus.
The Food and Drug Administration (FDA) has given emergency use authorization to one type of COVID-19 vaccine and approval to two vaccines. Coronaviruses have a spikelike structure on their surface called an S protein.
Messenger RNA (mRNA) vaccines give your cells instructions to build a harmless piece of an S protein. Viral vector vaccines place genetic material from the COVID-19 virus into a weakened version of a different virus. When this different virus enters your cells, it delivers genetic material from the COVID-19 virus that gives your cells instructions to make copies of the S protein. Both vaccines then cause the immune system to make antibodies to fight the COVID-19 virus.
The Novavax COVID-19, adjuvanted vaccine is a protein subunit vaccine. These vaccines include only the parts (proteins) of a virus that best stimulate your immune system.
The Novavax COVID-19 vaccine contains harmless S proteins. It also has an ingredient called an adjuvant that helps with your immune system response. Once your immune system recognizes the S proteins, this vaccine creates antibodies and defensive white blood cells. If you later become infected with the COVID-19 virus, the antibodies will fight the virus.