Pfizer and Moderna vaccines are both mRNA vaccines. These are virus fragments, not the virus itself, that are injected into the host. Conventional vaccines contain either antibodies or attenuated viruses, but inoculation is critical for the development of adaptive immunity. Without the entire virus, the mRNA vaccine is sufficient to provide this protection. This sequence is sufficient to generate the virus's protein spikes, allowing the body to be exposed to the virus's protein.