WANG-HUEI SHENGWang, Chung-ChengChung-ChengWangChu, Ching-ChiChing-ChiChuLin, Yueh-JuhYueh-JuhLinSUI-YUAN CHANGIeong, Si-ManSi-ManIeongSHAN-CHWEN CHANG2022-09-062022-09-0620230929-6646https://scholars.lib.ntu.edu.tw/handle/123456789/618546We reported 25 recipients (14 females and 11 males) aged from 18 to 65 years who unexpectedly received a primary dose of undiluted BNT162b2 vaccine (180 μg). The most common adverse reactions included injection site pain (n = 22), followed by fever (9), fatigue (8), chest tightness (6), and dizziness (6). The most common laboratory abnormalities were anemia (n = 4) and elevated liver transaminase level (4), followed by abnormal leukocyte counts (3) and elevated D-dimer level (3). The adverse reactions and laboratory abnormalities of these recipients were mild and spontaneously recovered within a few weeks. Significant elevations of anti-SARS-CoV-2 spike IgG titers after a booster dose of the BNT162b2 were found. Similar to reports of BNT162b2 clinical trials, the adverse reactions and laboratory abnormalities of these recipients were mild, and they spontaneously recovered within a few weeks. These results provide clinical and immunological effects of undiluted BNT162b2 vaccine inoculation.enAdverse events; Coronavirus disease 2019 (COVID-19); Immune response; Undiluted BNT162b2 vaccine[SDGs]SDG3journal article10.1016/j.jfma.2022.07.009359778672-s2.0-85135959516https://api.elsevier.com/content/abstract/scopus_id/85135959516