After 6 months of adenovirus vaccination, a booster injection can be given intramuscularly in the deltoid muscle of the upper arm. Adenovirus vaccine is the full name of the adenovirus-vectored neocoronavirus vaccine, which mainly recombines the neocoronavirus spiking glycoprotein gene into the genome of the replication-defective human adenovirus type 5. The recombinant adenovirus expresses the neocoronavirus S-protein antigen in vivo, inducing the body to generate humoral immunity and cellular immune response to provide dual immune protection. In general, adenovirus vaccines require only one dose to achieve a high level of immunoprotection. However, the antibodies produced by the body after one dose of vaccination may gradually fade away, which generally means that the antibody titer starts to weaken 6 months after vaccination. At this time, supplemental vaccination can be given to maintain a high level of immunity again. The adenovirus booster shot is administered in the same way as the first vaccination, i.e., it is injected into the deltoid muscle of the upper arm, where there are relatively more immune cells for better antibody production.