Supporting data for “Novel RNA Adjuvant for Intradermal Influenza and COVID-19 Vaccine”

In this project, we first established a mouse model with optimal virus inoculum and vaccine dosage to screen intradermal adjuvants. Next, we determined whether the combination of TLR9 and TLR7 agonists has superior adjuvant efficacy than TLR9 alone or TLR7 alone. Finally, we tested the efficacy of a novel RNA adjuvant, R266, an RNA derived from the 5’ untranslated region of the SARS-CoV-2 genomic sequence. R266 can improve the survival rate of mice infected with a lethal dose of influenza virus even when only one-sixth of the dose of previous influenza vaccines was immunized. We demonstrated the mechanism of R266 from B cell response and T cell response of mice and found that a powerful T cell response in the early stages of infection might be one key factor in increasing vaccine protection.

In conclusion, we demonstrated that R266 could be used as a promising intradermal adjuvant to enhance the effectiveness of the influenza vaccine. Further detailed mechanisms of R266 are worth exploring, which will lay the foundation for future innovations in RNA adjuvants and vaccines.