Three participants with no history of COVID-19 were on immunosuppressive therapy: two were regular with their immunosuppressive medications, including one on a combination of corticosteroids and benralizumab for asthma and eosinophilic sinusitis and one on a combination of azathioprine, mesalazine, and golimumab for ulcerative colitis; the additional was being temporarily treated with corticosteroids for pharyngitis and laryngeal edema by an otolaryngologist from 13 to 17 days after the first vaccination. having a prevalence of 100% at 35 days after the first vaccination. The multivariate log-normal linear regression analysis indicated the effect of immunosuppressant medication using both the Abbott (p=0.013) and Fujirebio (p=0.039) assays on S-IgG levels after complete vaccination. Pearson’s correlation coefficient between the Abbott and Fujirebio S-IgG results in all 300 samples collected before and after vaccination and 50 positive settings from individuals with coronavirus disease 2019 were 0.963 [95% confidence interval (CI): 0.954-0.970, p0.001] and 0.909 (95% CI: 0.845-0.948, p0.001), respectively. Summary The BNT162b2 mRNA vaccine was effective at increasing S-IgG levels in Japanese immunocompetent healthcare workers. The Fujirebio S-IgG assay showed high diagnostic accuracy, using the Abbott S-IgG assay as the research test. strong class=”kwd-title” Keywords: coronavirus disease 2019, immunoglobulin, neutralizing antibody, severe acute respiratory syndrome coronavirus 2, BNT162b2 mRNA vaccine, anti-spike protein immunoglobulin G Intro Coronavirus disease 2019 (COVID-19) is an acute respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has become a general public health and economic problem worldwide since December 2019, continuing through April 2021 (1). To conquer this unprecedented pandemic, numerous vaccines against SARS-CoV-2 have been developed (2). In Japan, the government initiated the initial vaccination of healthcare workers (HCWs) in February 2021 with BNT162b2 mRNA vaccine manufactured by Pfizer-BioNTech. The vaccine against SARS-CoV-2 generates antibodies that target the spike protein on the surface of the virus, thereby avoiding illness and severe disease (3-5). Epidemiological studies are required to assess the performance of vaccines for safety against illness and disease, but they take a long time to perform and cannot assess susceptibility to SARS-CoV-2 illness at the individual level. To quickly assess the effect of a vaccine, neutralizing antibodies can be measured as an indication of humoral immunity to determine the immunogenicity of the vaccine (6,7), and cellular immunity can be checked (8,9). In the early phases of vaccination, studies from additional countries, including Japan, have reported that neutralizing antibodies increase after vaccination (6,7). However, it is hard to measure neutralizing antibody titers in general hospitals due to the complexity of the measurement. Numerous antibody assays have been developed in other countries (10-13). Studies from additional countries have reported that neutralizing antibodies are primarily anti-spike protein immunoglobulin G (S-IgG), and the ARCHITECT SARS-CoV-2 IgG Quant, which actions S-IgG and is promoted by Abbott (Abbott Park, Chicago, USA), correlates with neutralizing antibodies (14,15). A set of Japanese assays, including for S-IgG, was recently developed and launched by Fujirebio (Tokyo, Japan) like a commercially available antibody test that can be performed under standard Granisetron Hydrochloride laboratory safety conditions without complicated processes. In the present study, to verify the immunogenicity of the BNT162b2 mRNA vaccine in the Japanese population, we measured the S-IgG levels using the Abbot and Fujirebio assays before and after vaccination. In Rabbit Polyclonal to VTI1A addition, to validate the overall performance of the Fujirebio assay, we assessed the antibody response using the Fujirebio assay for S-IgG, anti-spike protein immunoglobulin M (S-IgM), and anti-nucleocapsid protein IgG (N-IgG) before and after vaccination and in positive and negative controls. Materials and Methods Study design and establishing This single-center prospective observational study was carried out at Shonan Fujisawa Tokushukai Hospital, Kanagawa, Japan. In Japan, the BNT162b2 vaccine was the 1st SARS-CoV-2 vaccine to become Granisetron Hydrochloride available, which is recommended to be given intramuscularly through two doses, three weeks apart. In accordance with the Japanese government-led vaccination routine, vaccination of the general public using the BNT162b2 vaccine began in February 2021 for HCWs in a limited number of designated hospitals. In our hospital, vaccination of HCWs was started in April 2021, and all 1,033 HCWs who wished to become vaccinated completed their second dose Granisetron Hydrochloride in May 2021. Participants HCWs at our hospital who have been 20 years older and wished to become vaccinated were eligible for enrollment. Those who experienced a history of SARS-CoV-2 illness were allowed to participate, offered they had completed the isolation period and experienced clinically recovered. Potential participants were excluded if they met any of the Granisetron Hydrochloride following conditions: 1) experienced already received a COVID-19 vaccine, 2) were in the active phase of COVID-19, 3) did not wish to become vaccinated of their personal choice, or 4) did not provide their educated consent. One hundred consecutive vaccinees were enrolled in this study from April to May 2021 and were followed up until June 2021. The prospective sample size of 100 was based on feasibility in terms of the budget and workload. All participants were asked if they were on immunosuppressive therapy or cytotoxic anticancer.