Antibody Response to Sars-CoV-2 in Adults After 18 Months of Second Dose Vaccination of Astra ZenecaSarwo Handayani, Khariri, Masri Sembiring Maha, Helena Ullyartha Pangaribuan, Syarif Hidayat, Telly Purnamasari and Tonang Dwi ArdyantoBIO Web Conf., 101 (2024) 04001DOI: https://doi.org/10.1051/bioconf/202410104001