Swine enteric coronaviruses (SECoVs), including transmissible gastroenteritis virus (TGEV), porcine epidemic diarrhea virus (PEDV), porcine deltacoronavirus (PDCoV), and swine acute diarrhea syndrome coronavirus (SADS-CoV), are major enteric pathogens causing severe diarrhea, dehydration, high neonatal mortality, and substantial global economic losses. Rapid viral evolution and recombination continually generate antigenically diverse variants that limit cross-protection and undermine vaccine efficacy, particularly for PEDV genogroup II strains that now dominate worldwide circulation. This review synthesizes current knowledge on epidemiology, diagnostic innovations, and emerging vaccine platforms, with emphasis on advances since 2022. Recent progress includes molecular surveillance tools, rapid point-of-care diagnostics, and next-generation vaccine technologies such as mRNA-based and virus-like particle platforms. However, significant knowledge gaps persist regarding viral evolution dynamics, co-infection synergies, and zoonotic spillover potential, particularly following documented human infections with PDCoV. Effective long-term control requires integrated genomic surveillance, strengthened farm-level biosecurity, rationally designed multivalent vaccines targeting conserved epitopes, and harmonized international surveillance systems to reduce outbreak risk and enhance pandemic preparedness at the human–animal interface.

Porcine epidemic diarrhea (PED) continues to inflict devastating losses on global swine production. By systematically reviewing and meta-analysing 32 high-quality studies, we quantified the protective efficacy of PED vaccines and dissected how core variables shape that protection. Using fecal scores as the endpoint, we pooled effect sizes under a random-effects model and explored sources of heterogeneity through subgroup analyses. This analysis showed a pooled effect size (Hedges’ g) of −5.80, confirming that vaccination markedly alleviates diarrheal severity. Moreover, substantial heterogeneity was detected across studies. Stratified analyses revealed that vaccine type, vaccination target, vaccination route, and vaccination frequency are the principal sources of variation, all of which significantly influence vaccine efficacy. Conventional inactivated or live-attenuated formulations still dominate the field, but recombinant live-viral platforms are emerging. Piglets and sows represent the most responsive immunological targets. A two-dose regimen consistently outperforms a single injection, and delivery via intranasal, oral or intramuscular routes offers distinct advantages that can be exploited to maximise mucosal and systemic immunity. Overall, the optimal impact on PED prevention and control is achieved when the vaccine is correctly chosen and paired with an appropriate immunization protocol and delivery route.

Rapid and accurate pathogen detection is crucial to mitigating the significant economic impacts of infectious animal diseases. Recombinase-aided amplification (RAA) has emerged as a highly promising isothermal diagnostic tool, characterized by its rapid turnaround time, robust amplification efficiency, and single-copy analytical sensitivity. In veterinary diagnostics, RAA has evolved from single-pathogen proof-of-concept assays to become a promising technology for point-of-care scenarios. This review critically evaluates the integration of RAA with real-time fluorescence, CRISPR-Cas systems, lateral flow dipsticks (LFDs), and suspension microarray technologies, highlighting their impact on assay sensitivity and point-of-care (POC) applicability. Despite recent advancements, including encouraging progress in multiplexing and expanded applications in companion animal medicine, inherent challenges such as matrix effects in crude clinical samples, aerosol contamination risks, and commercialization barriers remain. By benchmarking RAA against traditional molecular methods and structurally similar technologies like recombinase polymerase amplification (RPA), this review outlines future trajectories for optimizing RAA platforms, aiming to maximize their utility in routine veterinary surveillance and epidemiological control.

Porcine epidemic diarrhea virus (PEDV) continues to undergo persistent genetic evolution and remains highly prevalent in pig herds worldwide. The resulting porcine epidemic diarrhea (PED) causes substantial economic losses to the global commercial swine industry. In this study, 296 clinical specimens were collected from diarrheic piglets across nine districts and counties of Chongqing between 2022–2024 and were screened using RT-qPCR. PEDV-positive specimens were detected in all sampling regions, with an overall positive rate of 48.31% (143/296), indicating widespread circulation and endemic persistence of PEDV throughout Chongqing. Phylogenetic analysis of the S gene from 15 representative field isolates revealed that all strains clustered within the G2c sublineage, implying that G2c has become the predominant epidemic lineage circulating in this region in recent years. Sequence analysis showed that the nucleotide identities of the S gene ranged from 93.37%–94.09% compared with the classic CV777 strain and from 96.79%–97.67% compared with the variant AJ1102 strain. Corresponding amino acid similarities were 92.88%–93.56% and 97.25%–98.05%, respectively. Notably, clear recombination footprints were identified in 11 sequenced isolates, all exhibiting highly identical recombination patterns, likely resulting from crossover events between the major parental strain FR/001/2014 and the minor parental strain CH/GDGZ/2012. Furthermore, ten distinct amino acid substitutions including F536L, D566E and L573S were identified within the COE antigenic domain of the S protein, whereas the SS2, SS6 and 2C10 domains remained highly conserved. Four isolates possessed four novel potential N-glycosylation motifs, including 300 NKTI and 787 NFSV, while two isolates concurrently lost the conserved 341 NLSF glycosylation site. These genetic alterations may influence viral pathogenicity and immune evasion capacity, thereby potentially contributing to the continued predominance and spread of the G2c sublineage in China. Together, this study expands current epidemiological knowledge of PEDV in inland Southwest China, and confirms G2c strains as the dominant circulating variants in local pig populations. These findings provide important molecular insights into the epidemiological trends and evolutionary dynamics of PEDV and offer a valuable reference for the development of more effective prevention and control strategies.

Porcine epidemic diarrhea virus (PEDV) continues to undergo genetic evolution and remains a major etiological agent of enteric disease in swine, causing significant economic losses worldwide. This study investigated the molecular epidemiology and genetic characteristics of PEDV circulating in Chongqing, China, between 2022 and 2024. A total of 296 diarrheic piglet samples collected from nine regions were screened using RT-qPCR, of which 48.31% (143/296) tested positive for PEDV. A subset of positive samples was subjected to S gene amplification and sequencing, yielding 15 complete sequences. Phylogenetic analysis revealed that all sequenced strains clustered within the G2c lineage and showed high nucleotide similarity (93.37–94.09%) to the classical CV777 strain. Recombination analysis indicated potential recombination events among field strains involving S-INDEL and G2b-like parental lineages, although these findings are based on a limited number of sequences. Sequence analysis identified multiple amino acid substitutions within the COE antigenic region, while other neutralizing epitopes (SS2, SS6, and 2C10) remained largely conserved. In addition, variation in predicted N-glycosylation sites was observed among some strains. Structural modelling suggested that these changes may influence spike protein conformation and antigenic properties; however, these interpretations are based on in silico analysis and require experimental validation. Overall, the findings indicate ongoing genetic evolution of PEDV in Chongqing and suggest circulation of G2c-associated variants in diarrheic piglets. However, given the limited and non-random nature of sequencing, these results may not fully represent the broader viral population. Continued large-scale molecular surveillance and functional studies are needed to better understand PEDV evolution and to support the development of improved control strategies and vaccines.