Yang Huijie, Xie Ying, Li Changgui
Divsion of respiratory virus vaccines, National Institutes for Food and Drug Control, Beijing, China.
Institute of Medical Biology, Chinese Academy of Medical Science and Peking Union Medical College, Kunming, China.
Expert Rev Vaccines. 2023 Jan-Dec;22(1):186-192. doi: 10.1080/14760584.2023.2174529.
Multiple COVID-19 vaccines have been approved and employed in the fight against the pandemic. However, these vaccines have limited long-term effectiveness against severe cases and a decreased ability to prevent mild disease.
This review discusses the relevant factors influencing the efficacy of the vaccines against mild and severe infection, analyzes the possible underlying mechanisms contributing to the different outcomes in terms of vaccine function and disease progression, and proposes improvements for the next generation of vaccines.
The reduced efficacy of the COVID-19 vaccine in the prevention of viral infection is closely related to the emergence of novel SARS-CoV-2 variants and their rapid transmission ability. Fundamentally, the immune responses induced by COVID-19 vaccines cannot effectively halt virus replication in the upper respiratory tract because only a limited number of specific antibodies reach these areas and decrease in concentration over time. However, the established immune response can provide sufficient protection against severe diseases by blocking viral infection of the lower respiratory tract or lung owing to sufficient antibody repertoires and memory responses. Considering this situation, future COVID-19 vaccines should have the potential to replenish the mucosal immune response in the respiratory tract to prevent viral infection.
多种新冠疫苗已获批准并用于抗击疫情。然而，这些疫苗对重症病例的长期有效性有限，预防轻症疾病的能力也有所下降。
本综述讨论了影响疫苗对轻症和重症感染疗效的相关因素，从疫苗功能和疾病进展方面分析了导致不同结果的潜在机制，并对下一代疫苗提出了改进建议。
新冠疫苗预防病毒感染的效力降低与新型严重急性呼吸综合征冠状病毒2（SARS-CoV-2）变体的出现及其快速传播能力密切相关。从根本上说，新冠疫苗诱导的免疫反应无法有效阻止病毒在上呼吸道复制，因为只有有限数量的特异性抗体到达这些部位，且其浓度会随时间下降。然而，已建立的免疫反应可通过阻断病毒在下呼吸道或肺部的感染，凭借充足的抗体库和记忆反应为重症疾病提供充分保护。考虑到这种情况，未来的新冠疫苗应具备补充呼吸道黏膜免疫反应以预防病毒感染的潜力。
