Sunagar Raju, Singh Amit, Kumar Sudeep
Ella Foundation, Hyderabad 500078, India.
Department of Immunology and Microbial Disease, Albany Medical College, Albany, NY 12208, USA.
Vaccines (Basel). 2023 Apr 15;11(4):849. doi: 10.3390/vaccines11040849.
The global rollout of COVID-19 vaccines has played a critical role in reducing pandemic spread, disease severity, hospitalizations, and deaths. However, the first-generation vaccines failed to block severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and transmission, partially due to the limited induction of mucosal immunity, leading to the continuous emergence of variants of concern (VOC) and breakthrough infections. To meet the challenges from VOC, limited durability, and lack of mucosal immune response of first-generation vaccines, novel approaches are being investigated. Herein, we have discussed the current knowledge pertaining to natural and vaccine-induced immunity, and the role of the mucosal immune response in controlling SARS-CoV2 infection. We have also presented the current status of the novel approaches aimed at eliciting both mucosal and systemic immunity. Finally, we have presented a novel adjuvant-free approach to elicit effective mucosal immunity against SARS-CoV-2, which lacks the safety concerns associated with live-attenuated vaccine platforms.
2019冠状病毒病（COVID-19）疫苗的全球推广在减少疫情传播、疾病严重程度、住院率和死亡率方面发挥了关键作用。然而，第一代疫苗未能阻断严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的感染和传播，部分原因是黏膜免疫诱导有限，导致关注变异株（VOC）不断出现和突破性感染。为应对第一代疫苗面临的VOC挑战、有限的持久性和缺乏黏膜免疫反应问题，正在研究新的方法。在此，我们讨论了有关天然免疫和疫苗诱导免疫的现有知识，以及黏膜免疫反应在控制SARS-CoV-2感染中的作用。我们还介绍了旨在引发黏膜和全身免疫的新方法的现状。最后，我们提出了一种新的无佐剂方法来引发针对SARS-CoV-2的有效黏膜免疫，该方法不存在与减毒活疫苗平台相关的安全问题。
