Immunogenicity and protective efficacy of canine enteric coronavirus vaccine: a systematic review and meta-analysis.

Abstract

BACKGROUND: Canine enteric coronavirus (CECoV) causes diarrhea and vomiting, often leading to outbreaks in kennels and shelters. The World Small Animal Veterinary Association does not recommend vaccination due to limited evidence of efficacy. This meta-analysis assesses CECoV vaccine immunogenicity and protective efficacy against diarrhea and viral shedding. METHODS: PubMed, Scopus, and Google Scholar were searched for experimental or observational studies of dogs vaccinated against CECoV, published from inception to September 29, 2025. Included studies confirmed dogs were free of CECoV infection and neutralizing antibodies before study. Exclusions applied to noncompliant studies. The Systematic Review Centre for Laboratory Animal Experimentation and funnel plots assessed bias risk. To assess vaccine immunogenicity, ELISA optical density (OD) values and log2 virus neutralization (VN) titers were regressed; pooled risk ratios evaluated protective efficacy. RESULTS: From 415 studies, 5 experimental studies with unclear bias risks were included. Most reported dog age but omitted sex or breed. Inactivated vaccines significantly increased both OD values and VN titers, whereas attenuated vaccines significantly increased OD values but not VN titers. Vaccination reduced diarrhea risk by 72% (risk ratio, -1.28; 95% CI, -2.05 to -0.51), but did not decrease viral shedding (risk ratio, -0.25; 95% CI, -0.70 to 0.21). CLINICAL RELEVANCE: CECoV vaccines are immunogenic and reduce diarrhea, but do not significantly reduce viral shedding, potentially masking infections in clinical settings and thus complicating disease control in communal environments. Limited literature and studies from similar research groups suggest removing CECoV vaccines from guidelines. Standardized reporting is recommended to improve future canine epidemiological research reliability.