The unprecedented impact of the coronavirus disease 2019 (COVID-19) pandemic has resulted in global challenges to our health-care systems and our economic security. As such, there has been significant research into all aspects of the disease, including diagnostic biomarkers, associated risk factors, and strategies that might be used for its treatment and prevention. Toward this end, eosinopenia has been identified as one of many factors that might facilitate the diagnosis and prognosis of severe COVID-19. However, this finding is neither definitive nor pathognomonic for COVID-19. While eosinophil-associated conditions have been misdiagnosed as COVID-19 and others are among its reported complications, patients with pre-existing eosinophil-associated disorders (e.g., asthma, eosinophilic gastrointestinal disorders) do not appear to be at increased risk for severe disease; interestingly, several recent studies suggest that a diagnosis of asthma may be associated with some degree of protection. Finally, although vaccine-associated aberrant inflammatory responses, including eosinophil accumulation in the respiratory tract, were observed in preclinical immunization studies targeting the related SARS-CoV and MERS-CoV pathogens, no similar complications have been reported clinically in response to the widespread dissemination of either of the two encapsulated mRNA-based vaccines for COVID-19.

2019 年冠状病毒病 (COVID-19) 大流行造成了前所未有的影响，给我们的医疗保健系统和经济安全带来了全球性挑战。因此，对该疾病的各个方面都进行了大量研究，包括诊断生物标志物、相关风险因素以及可用于治疗和预防的策略。为此，嗜酸性粒细胞减少症已被确定为可能有助于重症 COVID-19 诊断和预后的众多因素之一。然而，这一发现对于 COVID-19 既不是决定性的，也不是诊断性的。虽然嗜酸性粒细胞相关疾病被误诊为 COVID-19，并且其他并发症属于已报告的并发症，但患有嗜酸性粒细胞相关疾病（例如哮喘、嗜酸性胃肠道疾病）的患者似乎不会增加患严重疾病的风险；有趣的是，最近的几项研究表明，哮喘的诊断可能与某种程度的保护有关。最后，尽管在针对相关 SARS-CoV 和 MERS-CoV 病原体的临床前免疫研究中观察到了与疫苗相关的异常炎症反应，包括呼吸道中嗜酸性粒细胞积聚，但临床上尚未报告类似的并发症，以应对疫苗的广泛传播。两种基于 mRNA 的封装疫苗中的任何一种适用于 COVID-19。