Abstract

The impact of SARS-CoV-2 and COVID-19 disease susceptibility varies depending on the age and health status of an individual. Currently, there are more than 140 COVID-19 vaccines under development. However, the challenge will be to induce an effective immune response in the elderly population. Analysis of B cell epitopes indicates the minor role of the stalk domain of spike protein in viral neutralization due to low surface accessibility. Nevertheless, the accumulation of mutations in the receptor-binding domain (RBD) might reduce the vaccine efficacy in all age groups. We also propose the concept of chimeric vaccines based on the co-expression of SARS-CoV-2 spike and influenza hemagglutinin (HA) and matrix protein 1 (M1) proteins to generate chimeric virus-like particles (VLP). This review discusses the possible approaches by which influenza-specific memory repertoire developed during the lifetime of the elderly populations can converge to mount an effective immune response against the SARS-CoV-2 spike protein with the possibilities of designing single vaccines for COVID-19 and influenza.

• Highlights

• Immunosenescence aggravates COVID-19 symptoms in elderly individuals.

• Low immunogenicity of SARS-CoV-2 vaccines in elderly population.

• Tapping the memory T and B cell repertoire in elderly can enhance vaccine efficiency.

• Chimeric vaccines can mount effective immune response against COVID-19 in elderly.

• Chimeric vaccines co-express SARS-CoV-2 spike and influenza HA and M1 proteins.

 抽象的

SARS-CoV-2 和 COVID-19 疾病易感性的影响因个人的年龄和健康状况而异。目前，有超过 140 种 COVID-19 疫苗正在开发中。然而，挑战将是在老年人群中诱导有效的免疫反应。 B 细胞表位分析表明，由于表面可及性较低，刺突蛋白的茎结构域在病毒中和中的作用较小。然而，受体结合域（RBD）突变的积累可能会降低所有年龄段的疫苗功效。我们还提出了嵌合疫苗的概念，该疫苗基于 SARS-CoV-2 刺突和流感血凝素 (HA) 和基质蛋白 1 (M1) 蛋白的共表达，以生成嵌合病毒样颗粒 (VLP)。本综述讨论了老年人群一生中形成的流感特异性记忆库可以汇聚起来对 SARS-CoV-2 刺突蛋白产生有效免疫反应的可能方法，并有可能设计针对 COVID-19 的单一疫苗和流感。

•  亮点

• 
  免疫衰老会加重老年人的 COVID-19 症状。

• 
  SARS-CoV-2 疫苗在老年人群中的免疫原性较低。

• 
  利用老年人的记忆 T 和 B 细胞库可以提高疫苗效率。

• 
  嵌合疫苗可以在老年人中针对 COVID-19 产生有效的免疫反应。

• 
  嵌合疫苗共表达 SARS-CoV-2 刺突蛋白以及流感 HA 和 M1 蛋白。