During the first half of 2020, coronavirus disease 2019 (COVID-19) spread rapidly worldwide, with no vaccines or antiviral agents available. In Japan, patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were required to obtain two consecutive negative PCR results or complete a 14-day isolation period before returning to work 1. The circulating virus at that time was the original SARS-CoV-2 strain, which frequently caused gustatory and olfactory disturbances 2 and utilized angiotensin-converting enzyme 2 as its cellular entry receptor. We encountered two contrasting cases of mild COVID-19 in close colleagues with similar physical characteristics who were followed at the same medical institution. Because their exposure circumstances and clinical backgrounds were comparable, it was possible to directly assess differences in the timing of viral clearance in relation to the use of shosaikotokakikyosekko (SSKKS), a traditional Kampo formula. A 27-year-old man with no chronic medical conditions presented in late April 2020 with mild malaise after close contact with Case Z during the presymptomatic phase. His height was 170 cm, weight 68 kg, and BMI 23.5. Kampo examination revealed a superficial exterior pattern with adequate physical strength, and mild nasal discharge was noted. A polymerase chain reaction (PCR) test for SARS-CoV-2 was positive at the initial visit. Four days later, he developed taste and smell disturbances. SSKKS (7.5 g/day; Tsumura TJ-109) was initiated to support recovery of the nasal and pharyngeal mucosa. No other medications were used. His chemosensory symptoms improved 4 days after starting SSKKS, and his PCR test became negative 7 days after the initial consultation (Figure 1). A 26-year-old man with no chronic medical conditions presented 3 days earlier with low-grade fever and mild sore throat. SARS-CoV-2 infection was confirmed by PCR. His height was 168 cm, weight 67 kg, and BMI 23.5. Kampo assessment showed a superficial pulse pattern without other notable findings. His symptoms resolved rapidly, and he remained asymptomatic thereafter. No medications were administered, and he was managed by observation alone. His PCR test remained positive for 17 days (at least 14 days after symptom onset) before turning negative (Figure 1). Recent reports have described the use of Kampo formulas in acute-phase infectious and inflammatory conditions, including mild or persistent COVID-19, suggesting potential benefits in early-stage SARS-CoV-2 infection 3, 4. These observations support the possibility that SSKKS may contribute to earlier recovery in mild SARS-CoV-2 infection. However, no clinical data were available in early 2020 when these cases occurred. At that time, no antiviral agents had been approved, and infected individuals—including healthcare workers—were required to refrain from working for a designated period. Because prolonged viral shedding increases the risk of transmission and workforce strain, early viral clearance was of particular importance. SSKKS consists of shosaikoto, kikyo, and sekko, each traditionally regarded as having anti-inflammatory or mucosal-stabilizing properties. Shosaikoto has been reported to suppress Th2-type cytokines and reduce nitric oxide and interleukin-6 production 5. Kikyo may help stabilize mucosal surfaces and reduce pharyngeal inflammation, while sekko is considered to alleviate internal heat and maintain mucosal moisture. These combined actions may support epithelial repair in mild SARS-CoV-2 infection, in which viral replication is often localized to the upper airway. In this report, two close colleagues with similar physical characteristics and Kampo patterns exhibited markedly different viral clearance times. The earlier PCR negativity in Case X raises the possibility that SSKKS contributed to a more rapid recovery. This study is limited by its small sample size and observational design, and findings from the early pandemic context may not be generalizable. These two contrasting cases suggest that SSKKS may help stabilize mucosal surfaces and support earlier viral clearance in mild SARS-CoV-2 infection. Further studies are needed to clarify its potential role in early-stage COVID-19 management. H.W. designed the study, collected and analyzed the data, and drafted and revised the manuscript. I.N. and T.O. contributed to data interpretation and provided guidance on manuscript preparation. Y.Y. and A.I. provided critical comments and advice. All authors reviewed and approved the final manuscript. The authors thank the medical staff involved in the care of the patients. The authors have nothing to report. This study was approved by the Ethics Committee of Tokyo Medical University Hospital (Approval No. T2020-0161). The requirement for individual informed consent was waived because only existing medical records were used, and an opt-out process was implemented on the hospital website in accordance with institutional policy. The authors declare no conflicts of interest. All data generated or analyzed during this study are included in this article.
Watanabe et al. (Fri,) studied this question.