Exploration of the cross-immunity between SARS-CoV and SARS-CoV-2 in mice

Aim: This study aimed to develop a universal vaccine that can effectively address future outbreaks of coronavirus infections. Materials & methods: We developed recombinant DNA vaccines and vaccinia vector vaccines specific for SARS-CoV and SARS-CoV-2 and evaluated them in BALB/c mice. Both cellular and humoral immune responses were analyzed. Results: Compared with those immunized with the SARS-CoV or SARS-CoV-2 vaccine alone, the cross-immune group exhibited a 21.2-fold increase in cellular immune response, an over 80-fold increase in binding antibodies and a 136.7-fold increase in neutralizing antibodies. The combination of recombinant DNA and vaccinia vaccines induced a stronger immune response than DNA vaccine immunization alone. Conclusion: This study demonstrated that cross-immunization with different coronaviruses can induce a broad immune response.