Although SARS-CoV vaccines can protect against lethal infection, the addition of delta inulin-based polysaccharide adjuvant on day 3 post-challenge can significantly increase serum neutralizing-antibody titers and reduce lung virus titers. It also shows that immunity achieved with delta inulin adjuvants is long-lived, thereby overcoming the natural tendency for rapidly waning coronavirus immunity. This suggests that delta inulin polysaccharide adjuvants have the potential to develop more effective coronavirus vaccines [20]. In addition, some Chinese herbal medicinal polysaccharides have been used as safe and effective adjuvants [77,107,112,113]. APS as an adjuvant combined with influenza vaccine can improve the immune response and systemic humoral response to H5N1 virus infection [46,114]. APS can potentially be used as an immunomodulator for a foot-and-mouth disease virus (FMDV), which is an RNA virus vaccine, and provide better protection against FMDV [115]. APS is also a potent adjuvant for hepatitis B DNA vaccine, and can enhance the immune responses of HBV DNA vaccine via promoting dendritic cells maturation and inhibit the regulatory T cells frequency [116]. Polysaccharide extract from RI exerts potent anti-IAV activity against human seasonal influenza viruses (H1N1 and H3N2) and AIV (H6N2 and H9N2) in vitro [49]. The polysaccharides also significantly reduced the expression of pro-inflammatory cytokines (IL-6) and strongly inhibited the protein expression of TLR-3 induced by PR8. The polysaccharide extract from RI, therefore, has the potential to be used as an adjunct to antiviral therapy for the treatment of IAV infection [49].