An adenovirus-vectored recombinant vaccine confers passive immunity protection from swine acute diarrhea syndrome coronavirus challenge in neonatal mice.

Swine acute diarrhea syndrome coronavirus (SADS-CoV), an emerging bat-origin Alphacoronavirus with demonstrated zoonotic potential, poses a significant threat to swine health and has considerable economic implications. Currently, no licensed vaccines are available. We constructed a replication-deficient human adenovirus type 5 (Ad5) vectored vaccine candidate, rAd5-SADS-S, which expresses the SADS-CoV spike (S) glycoprotein. The rAd5-SADS-S vaccine elicited robust SADS-CoV-specific humoral immunity and potent cellular responses in both mice and pigs. Notably, rAd5-SADS-S conferred passive protection to neonatal mice against lethal SADS-CoV challenge. These findings establish a preclinical foundation for the development of SADS-CoV vaccines.