The latest results from the phase 3 COVID-19 vaccines trials have been very positive. These have shown that vaccinating people with the gene for SARS-CoV-2 spike protein can induce excellent protective immunity.
The spike protein is the focus of most COVID-19 vaccines as it is the part of the virus that enables it to enter our cells. Virus replication only happens inside cells, so blocking entry prevents more virus being made. If a person has antibodies that can recognize the spike protein, this should stop the virus in its tracks.