Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), has emerged as a serious threat to human health worldwide. Efficient disinfection of surfaces contaminated with SARS-CoV-2 may help prevent its spread. This study aimed to investigate the in vitro efficacy of 222-nm far-ultraviolet light (UVC) on the disinfection of SARS-CoV-2 surface contamination. Methods: We investigated the titer of SARS-CoV-2 after UV irradiation (0.1 mW/cm 2) at 222 nm for 10-300 seconds using the 50% tissue culture infectious dose (TCID 50). In addition, we used quantitative reverse transcription polymerase chain reaction to quantify SARS-CoV-2 RNA under the same conditions. Results: One and 3 mJ/cm 2 of 222-nm UVC irradiation (0.1 mW/cm 2 for 10 and 30 seconds) resulted in 88.5 and 99.7% reduction of viable SARS-CoV-2 based on the TCID 50 assay, respectively. In contrast, the copy number of SARS-CoV-2 RNA did not change after UVC irradiation even after a 5-minute irradiation. Conclusions: This study shows the efficacy of 222-nm UVC irradiation against SARS-CoV-2 contamination in an in vitro experiment. Further evaluation of the safety and efficacy of 222-nm UVC irradiation in reducing the contamination of real-world surfaces and the potential transmission of SARS-CoV-2 is needed.

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Transforming growth factor-β (TGF-β) is central during the pathogenesis of pulmonary fibrosis, in which the plasminogen activator inhibitor-1 (PAI-1) also has an established role. TGF-β is also known to be the strongest inducer of PAI-1. To investigate the link between PAI-1 and TGF-β in fibrotic processes, we evaluated the effect of SK-216, a PAI-1-specific inhibitor, in TGF-β-dependent epithelial-mesenchymal transition (EMT) and fibroblast to myofibroblast differentiation. In human alveolar epithelial A549 cells, treatment with TGF-β induced EMT, whereas co-treatment with SK-216 attenuated the occurrence of EMT. The inhibition of TGF-β-induced EMT by SK-216 was also confirmed in the experiment using murine epithelial LA-4 cells. Blocking EMT by SK-216 inhibited TGF-β-induced endogenous production of PAI-1 and TGF-β in A549 cells as well. These effects of SK-216 were not likely mediated by suppressing either Smad or ERK pathways. Using human lung fibroblast MRC-5 cells, we demonstrated that SK-216 inhibited TGF-β-dependent differentiation of fibroblasts to myofibroblasts. We also observed this inhibition by SK-216 in human primary lung fibroblasts. Following these in vitro results, we tested oral administration of SK-216 into mice injected intratracheally with bleomycin. We found that SK-216 reduced the degree of bleomycin-induced pulmonary fibrosis in mice. Although the precise mechanisms underlying the link between TGF-β and PAI-1 regarding fibrotic process were not determined, PAI-1 seems to act as a potent downstream effector on the pro-fibrotic property of TGF-β. In addition, inhibition of PAI-1 activity by a PAI-1 inhibitor exerts an antifibrotic effect even in vivo. These data suggest that targeting PAI-1 as a downstream effector of TGF-β could be a promising therapeutic strategy for pulmonary fibrosis.

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Introduction The BNT162b2 and mRNA-1273 COVID-19 vaccines are the main vaccines that have been used for mass vaccination in Japan. Information on adverse reactions to COVID-19 vaccines in the Japanese population is limited. Methods We conducted an online survey on self-reported adverse reactions in individuals who had received two doses of the BNT162b2 mRNA or mRNA-1273 vaccine. The incidence of adverse events after each dose of vaccine was investigated. Propensity score matching was used to compare the incidence of adverse reactions after the second dose of the BNT162b2 mRNA and mRNA-1273 vaccines. Results After the first and second doses of the BNT162b2 vaccine, and the first and second doses of the mRNA-1273 vaccine, 890, 853, 6401, and 3965 individuals, respectively, provided complete responses. Systemic reactions, including fever, fatigue, headache, muscle/joint pain, and nausea were significantly more common in females, individuals aged <50 years, and after the second dose. The incidence of injection site pain did not differ significantly according to the dose. The incidence of delayed injection site reactions after the first dose of mRNA-1273 vaccine was 3.9% and 0.8% among females and males, respectively, and 10.6% among females aged 30–69 years. Local and systemic reactions after the second dose, including fever, fatigue, headache, muscle/joint pain, nausea, and skin rash were more common in individuals who had received the mRNA-1273 vaccine. Conclusions Adverse reactions were more frequently reported in females, younger individuals, and after the mRNA-1273 vaccine.