Basic information about the COVID-19 vaccines based on World Health Organization data (available here).

• There are four main approaches to develop a vaccine against a virus, like SARS-CoV-2.
• All methods rely on APCs (antigen presenting cells) to initiate the immune response. Once the APC identifies components of the virus, it triggers immune cells. These cells are then enabled to recognize and neutralize the virus.
• Some vaccines also contain adjuvants to enhance the immune response, and RNA based vaccines are encapsulated into lipid nanoparticles to protect it and help it enter the body’s cells.