The coronavirus 2019 (COVID-19) pandemic is expected to linger. Decisions regarding initiation or continuation of disease-modifying therapy for multiple sclerosis have to consider the potential relevance to the pandemic. Understanding the mechanism of action and the possible idiosyncratic effects of each therapeutic agent on the immune system is imperative during this special time. The infectious side-effect profile as well as the route and frequency of administration of each therapeutic agent should be carefully considered when selecting a new treatment or deciding on risk mitigation strategies for existing therapy. More importantly, the impact of each agent on the future severe acute respiratory syndrome coronavirus type-2 (SARS-CoV-2) vaccine should be carefully considered in treatment decisions. Moreover, some multiple sclerosis therapies may have beneficial antiviral effects against SARS-CoV-2 while others may have beneficial immune-modulating effects against the cytokine storm and hyperinflammatory phase of the disease. Conventional injectables have a favorable immune profile without an increased exposure risk and therefore may be suitable for mild multiple sclerosis during the pandemic. However, moderate and highly active multiple sclerosis will continue to require treatment with oral or intravenous high-potency agents but a number of risk mitigation strategies may have to be implemented. Immune-modulating therapies such as the fumerates, sphinogosine-1P modulators, and natalizumab may be anecdotally preferred over cell-depleting immunosuppressants during the pandemic from the immune profile standpoint. Within the cell-depleting agents, selective (ocrelizumab) or preferential (cladribine) depletion of B cells may be relatively safer than non-selective depletion of lymphocytes and innate immune cells (alemtuzumab). Patients who develop severe iatrogenic or idiosyncratic lymphopenia should be advised to maintain social distancing even in areas where lockdown has been removed or ameliorated. Patients with iatrogenic hypogammaglobulinemia may require prophylactic intravenous immunoglobulin therapy in certain situations. When the future SARS-CoV-2 vaccine becomes available, patients with multiple sclerosis should be advised that certain therapies may interfere with mounting a protective immune response to the vaccine and that serological confirmation of a response may be required after vaccination. They should also be aware that most multiple sclerosis therapies are incompatible with live vaccines if a live SARS-CoV-2 vaccine is developed. In this article, we review and compare disease-modifying therapies in terms of their effect on the immune system, published infection rates, potential impact on SARS-CoV-2 susceptibility, and vaccine-related implications. We propose risk mitigation strategies and practical approaches to disease-modifying therapy during the COVID-19 pandemic.

预计 2019 年冠状病毒 (COVID-19) 大流行将持续存在。关于开始或继续对多发性硬化症进行疾病缓解治疗的决定必须考虑与大流行的潜在相关性。在这个特殊时期，必须了解每种治疗药物对免疫系统的作用机制和可能的特殊作用。在选择新的治疗方法或决定现有治疗的风险缓解策略时，应仔细考虑感染性副作用以及每种治疗药物的给药途径和频率。更重要的是，在治疗决策中应仔细考虑每种药物对未来严重急性呼吸综合征冠状病毒 2 型（SARS-CoV-2）疫苗的影响。而且，一些多发性硬化症疗法可能对 SARS-CoV-2 具有有益的抗病毒作用，而另一些疗法可能对细胞因子风暴和疾病的高炎症期具有有益的免疫调节作用。常规注射剂具有良好的免疫特性，不会增加暴露风险，因此可能适用于大流行期间的轻度多发性硬化症。然而，中度和高度活动性多发性硬化症将继续需要口服或静脉内高效药物治疗，但可能必须实施一些风险缓解策略。从免疫概况的角度来看，在大流行期间，免疫调节疗法（如富马酸盐、sphinogosine-1P 调节剂和那他珠单抗）可能比细胞消耗性免疫抑制剂更受欢迎。在细胞消耗剂中，选择性（ocrelizumab）或优先（克拉屈滨）去除 B 细胞可能比非选择性去除淋巴细胞和先天免疫细胞（阿仑单抗）更安全。应建议出现严重医源性或异质性淋巴细胞减少症的患者保持社交距离，即使在已解除或改善封锁的地区也是如此。在某些情况下，医源性低丙种球蛋白血症患者可能需要预防性静脉注射免疫球蛋白治疗。当未来的 SARS-CoV-2 疫苗可用时，应告知多发性硬化症患者某些疗法可能会干扰对疫苗的保护性免疫反应，并且在接种疫苗后可能需要对反应进行血清学确认。他们还应该意识到，如果开发了 SARS-CoV-2 活疫苗，大多数多发性硬化症疗法都与活疫苗不相容。在本文中，我们从对免疫系统的影响、已发表的感染率、对 SARS-CoV-2 易感性的潜在影响以及疫苗相关影响等方面对疾病缓解疗法进行了回顾和比较。我们提出了在 COVID-19 大流行期间缓解疾病的风险策略和实用方法。