There are four types of COVID-19 vaccines

There are several types of COVID-19 vaccines developed using different technologies. The four main types are: 1. mRNA Vaccines: These vaccines use messenger RNA to instruct cells to produce a protein that triggers an immune response. Examples include the Pfizer-BioNTech and Moderna vaccines. 2. Vector Vaccines: These vaccines use a modified version of a different virus (not the virus that causes COVID-19) to deliver instructions to cells to produce a protein that triggers an immune response. Examples include the Johnson & Johnson and AstraZeneca vaccines. 3. Protein Subunit Vaccines: These vaccines include harmless pieces of the virus (often proteins) that trigger an immune response without using the live virus that causes COVID-19. An example is the Novavax vaccine. 4. Inactivated or Live-Attenuated Vaccines: These vaccines use a killed version of the virus or a weakened form of the live virus to stimulate an immune response. Examples include the Sinopharm and Sinovac vaccines.