Specimen search items; saliva S protein-specific sIgA; saliva S protein-specific IgG; S protein-specific IgM in saliva is measured by ELISA. The search method is as follows: (1) Perform a PCR test to detect SARS-CoV-2 in all search subjects and confirm that it is negative. Next; (2) collect saliva with saliva. Search before; 1 month and 6 months after vaccination.

Specimen search items; saliva S protein-specific sIgA; saliva S protein-specific IgG; S protein-specific IgM in saliva is measured by ELISA. The search method is as follows: (1) Perform a PCR test to detect SARS-CoV-2 in all search subjects and confirm that it is negative. Next; (2) collect saliva with saliva. Search before; 1 month and 6 months after vaccination.