Table_1_Photodynamic nasal SARS-CoV-2 decolonization shortens infectivity and influences specific T-Cell responses.docx

BackgroundThe main objective was to evaluate the efficacy of intranasal photodynamic therapy (PDT) in SARS-CoV-2 mildly symptomatic carriers on decreasing the infectivity period. SARS-CoV-2-specific immune-stimulating effects and safety were also analysed.
MethodsWe performed a randomized, placebo-controlled, clinical trial in a tertiary hospital (NCT05184205). Patients with a positive SARS-CoV-2 PCR in the last 48 hours were recruited and aleatorily assigned to PDT or placebo. Patients with pneumonia were excluded. Participants and investigators were masked to group assignment. The primary outcome was the reduction in in vitro infectivity of nasopharyngeal samples at days 3 and 7. Additional outcomes included safety assessment and quantification of humoral and T-cell immune-responses.
FindingsPatients were recruited between December 2021 and February 2022. Most were previously healthy adults vaccinated against COVID-19 and most carried Omicron variant. 38 patients were assigned to placebo and 37 to PDT. Intranasal PDT reduced infectivity at day 3 post-treatment when compared to placebo with a β-coefficient of -812.2 (CI95%= -478660 – -1.3, p<0.05) infectivity arbitrary units. The probability of becoming PCR negative (ct>34) at day 7 was higher on the PDT-group, with an OR of 0.15 (CI95%=0.04-0.58). There was a decay in anti-Spike titre and specific SARS-CoV-2 T cell immunity in the placebo group 10 and 20 weeks after infection, but not in the PDT-group. No serious adverse events were reported.
InterpretationIntranasal-PDT is safe in pauci-symptomatic COVID-19 patients, it reduces SARS-CoV-2 infectivity and decelerates the decline SARS-CoV-2 specific immune-responses.

研究背景
本研究的主要目的为评估鼻内光动力疗法（intranasal photodynamic therapy, PDT）用于新型冠状病毒（SARS-CoV-2）轻症带毒者时缩短传染期的疗效，同时分析其诱导的新型冠状病毒特异性免疫激活效应与治疗安全性。

研究方法
本研究在某三级医院开展了一项随机安慰剂对照临床试验（临床试验注册号：NCT05184205）。招募近48小时内新型冠状病毒核酸聚合酶链反应（Polymerase Chain Reaction, PCR）检测呈阳性的患者，将其随机分配至鼻内光动力疗法组或安慰剂组，排除合并肺炎的患者。受试者与研究者均对分组情况设盲。本研究的主要结局为治疗后第3天与第7天鼻咽样本的体外传染性降低幅度；次要结局包括安全性评估，以及体液免疫与T细胞免疫应答的定量检测。

研究结果
本研究于2021年12月至2022年2月间招募受试者，多数为既往健康的新冠疫苗接种成年人，且多数感染奥密克戎变异株。共38例患者被分配至安慰剂组，37例被分配至鼻内光动力疗法组。与安慰剂组相比，鼻内光动力疗法可在治疗后第3天降低传染性，β系数（beta coefficient）为-812.2（95%置信区间：-478660 ~ -1.3，p<0.05），传染性单位为任意单位。治疗后第7天，鼻内光动力疗法组患者核酸转阴（Ct值>34）的概率更高，比值比（odds ratio, OR）为0.15（95%置信区间：0.04~0.58）。感染后10周与20周时，安慰剂组的抗刺突蛋白抗体滴度与新型冠状病毒特异性T细胞免疫均出现衰减，而鼻内光动力疗法组未观察到该现象。本研究未报告严重不良事件。

研究结论
鼻内光动力疗法在少症状新型冠状病毒感染患者中具有良好安全性，可降低新型冠状病毒传染性，并延缓新型冠状病毒特异性免疫应答的衰退。