Researchers from Shanghai Ruijin Hospital have discovered for the first time the molecular mechanism of how the three-booster inactivated COVID-19 vaccines can exert a potent antiviral effect.

They revealed that the three-booster inactivated vaccines promote the activation and maturation of monocytes by inducing “training innate immunity” in human body, and thus achieve antiviral effect.

A paper about the research led by QuJieming, Zhu Jiang, Li Qingyun and Chen Saijuan from the hospital affiliated with the Shanghai Jiao Tong University School of Medicine was published on the website of Cell on Wednesday.

The paper was the first to give a systematic description of the effect of inactivated vaccination on the immune response of Omicron-infected individuals.

Previous studies focused on the establishment of specific humoral immunity and cellular immune memory against the Omicron variant triggered by COVID-19 mRNA vaccines or inactivated virus vaccines, and whether the antiviral effect of inactivated vaccination involves the induction of “innate immune memory” remained unclear.