fect of vaccine.
•  Polysaccharides play important roles in antiviral nanomaterial and delivery system.
•  A new idea to develop COVID-19 vaccine combining polysaccharides and nanotechnology is proposed.

1  Introduction
The present outbreak of a coronavirus-associated acute respiratory disease called coronavirus disease 19 (COVID-19) has spread to >210 countries, which is rare among acute infectious diseases in recent years, and caused a great threat to global public health [1]. This disease was caused by severe acute respiratory syndrome coronavirus 2 (SAR