Antibody responses to BNT162b2 vaccination in Japan: Monitoring vaccine efficacy by measuring IgG antibodies against the receptor binding domain of SARS-CoV-2

BACKGROUNDTo fight severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), mass vaccination has begun in many countries. To investigate the usefulness of a serological assay to predict vaccine efficacy, we analyzed the levels of IgG, IgM, and IgA against the receptor binding domain (RBD) of SARS-CoV-2 in the sera from BNT162b2 vaccinated individuals in Japan. METHODSThis study included 219 individuals who received two doses of BNT162b2. The levels of IgG, IgM, and IgA against RBD were measured by enzyme-linked immunosorbent assay before and after the first and second vaccination, respectively. The relationship between antibody levels and several factors including age, gender, and hypertension were analyzed. Virus-neutralizing activity in sera was measured to determine the correlation with the levels of antibodies. A chemiluminescent enzyme immunoassay (CLEIA) method to measure IgG against RBD was developed and validated for the clinical setting. RESULTSThe levels of all antibody isotypes were increased after vaccination. Among them, RBD-IgG was dramatically increased after the second vaccination. The IgG levels in females were significantly higher than in males. There was a negative correlation between age and IgG levels in males. The IgG levels significantly correlated with the neutralizing activity. The CLEIA assay measuring IgG against RBD showed a reliable performance and a high correlation with neutralizing activity. CONCLUSIONSMonitoring of IgG against RBD is a powerful tool to predict the efficacy of SARS-CoV-2 vaccination and provides useful information in considering a personalized vaccination strategy for COVID-19.

Comparison between Risks Listed in the Risk Management Plan and the Product Labeling of the Drug Package Insert / 医薬品情報学

<b>Objective: </b>Currently, Risk Management Plans (RMPs), plan that provide new risk information about drugs, are published on the Pharmaceutical and Medical Devices Agency (PMDA) website.  The aim of this study was to compare enumerated risks in RMPs to the product labeling (PL) of the drug package insert.<br><b>Methods: </b>The risks listed in RMPs on the PMDA website were assessed on February 10, 2014.  We investigated the documentation of these risks on the PL.<br><b>Results: </b>Seven-hundred and eighty-five risks were enumerated in the RMPs of 77 drugs.  The enumerated risks were classified as “important identified risks” (66%), “important potential risks” (22%), and “important missing information” (12%).  Ninety-four percent of risks listed in RMPs were documented on the PL.  A portion of both the “important identified risks” and “important potential risks” groups were not documented on the PL.<br><b>Conclusion: </b>This study was clearly the relation between risks listed in RMPs and documents on the PL.  Because a portion of the risks listed in RMPs was not documented on the PL, RMPs provide more safety information.  It is necessary to better understanding their characteristics, considering RMPs are a new source of drug information.