A Paradigm Shift: The Reclassification of SARS-CoV-2 and Longitudinal Immune Responses in Japanese Healthcare Workers

Abstract

Under the aegis of the National Infectious Diseases Act, the virus transitioned from a category 2 menace to category 5, analogous to seasonal influenza. For this classification to be appropriate, a comprehensive assessment of the immune status of the Japanese population must be conducted to ensure adequacy. The current study has investigated the protracted immune responses of healthcare workers (HCWs) to SARS-CoV-2 in Japan. One year subsequent to the systematically implemented SARS-CoV-2 vaccination campaign among HCWs, humoral and cellular immune responses were sustained at levels as high as or higher than those immediately following the third booster vaccination. Persisting immunity has highlighted the resilience and lasting memory exhibited in HCW defense against the virus, suggesting that the classification of SARS-CoV-2 infection as a category 5 in Japan has appeared judicious.

Keywords

• SARS-CoV-2
• longitudinal immune response
• Japanese healthcare workers
• IgG to the spike protein
• cellular T-SPOT value