Effect of the third dose of BNT162b2 COVID-19 mRNA vaccine on anti-SARS-CoV-2 antibody levels in healthcare workers.

PURPOSE: Administration of three doses of Pfizer-BioNTech BNT162b2 COVID-19 mRNA vaccine was completed in Japan in the spring of 2022. This study aimed to evaluate the antibody responses, and kinetics of three doses of vaccine in healthcare workers (HCWs). PATIENTS AND METHODS: We conducted a longitudinal cohort study with HCWs, who had no history of COVID-19 or serologic evidence of SARS-CoV-2 infection, from a single hospital. Immunoglobulin G (IgG) titers of anti-SARS-CoV-2 spike protein (SP) and nucleocapsid protein (NP) titers were measured using an automated chemiluminescent enzyme immunoassay system. RESULTS: A total of 636 HCWs participated in the study. The anti-SP IgG titers decreased slowly after the second dose of the BNT162b2 vaccine in all participants, and robust antibody response was observed after the third dose of the vaccine. The peak anti-SP IgG titer after the third dose was approximately 4.1-fold higher than that after the first and second doses, and the rate of decrease in the anti-SP IgG titer after the third dose was significantly more gradual, than that after the second dose. After the second dose of vaccine, the antibody response was weaker in older participants than in younger participants, and in males than in females respectively, whereas the response to the third dose of vaccine did not differ significantly by sex or age. Adverse events following immunization were generally mild to moderate. CONCLUSION: The third dose of the BNT162b2 vaccine induced a significant and sustained increase in anti-SP IgG titers, and was generally safe and well-tolerated.

[The Resources and Management Necessary for the Activities of a Disaster Medical Assistance Team].

It may not be common for laboratory tests to be employed immediately after a disaster in front-line healthcare settings. However, this is not because laboratory tests are not needed in post-disaster healthcare settings, but because the implementation of triage, which prioritizes the saving of lives, is the initial aim of a Disaster Medical Assistance Team (DMAT). Disaster response ability has been reported to be exerted according to the level of experience. After the Great East Japan earthquake, by the cooperation of related societies and organizations, diagnostic reagents and instruments were supplied to 3 core university hospitals in the affected areas, contributing to building a system whereby necessary medical items could be obtained in three affected Prefectures of the Tohoku region. We should always remember that front-line medical care activities in affected areas are possible due to the backup provided by logistic support teams. The more the system for DMAT is improved, the more effective the support system will be after the super-acute phase of a disaster. [Review].