The high antigenic variability of the foot-and-mouth disease virus (FMDV) represents a challenge for developing prophylactic strategies, stressing the need for research into vaccines offering broad protection against a range of virus strains. Here, the heterotypic cross-reaction using different vaccine schemes against serotype O strains was studied, evaluating the impact of revaccination, antigen dose, and incorporation of additional FMDV serotypes. Naïve cattle were immunized with seven distinct FMDV vaccines, receiving three doses of the same formulation at 0, 28, and 56 days post-primary vaccination (dpv). Serum samples were collected up to 70 dpv and tested by a virus-neutralizing test against serotype O strains from a South American lineage and two strains representative of two Asian lineages. Our results showed that vaccines containing the ME-SA topotype O1/Campos strain developed cross-neutralizing responses against the two Asian viruses after the first vaccination. In contrast, significant heterotypic neutralizing antibody titers against the homologous topotype strain were only found after the second vaccination, indicating that the phylogenic relationship may differ from the antigenic profiles for these two viruses. The amount of the O1/Campos strain and the revaccination were essential factors for neutralization against the homologous- and heterologous-type O FMDV viruses. The strain composition of the vaccine was only relevant for cross-neutralization against one of the Asian strains, suggesting potential intra-serotypic divergences for this pattern.

The high antigenic variability of the foot-and-mouth disease virus (FMDV) represents a challenge for developing prophylactic strategies, stressing the need of research into vaccines offering broad protection against a range of virus strains. Here, the heterotypic cross-reaction using different vaccine schemes against serotype O strains was studied, evaluating the impact of revaccination, antigen dose, and incorporation of additional FMDV serotypes. Naïve cattle were immunized with seven distinct FMDV vaccines, receiving three doses of the same formulation at 0, 28 and 56 days post-primary vaccination (dpv). Serum samples were collected up to 70 dpv and tested by a virus-neutralizing test against serotype O strains from South American and two strains representative two Asian lineages. Our results showed that vaccines containing the ME-SA topotype O1/Campos strain developed cross-neutralizing responses against the two Asian viruses after the first vaccination. In contrast, significant heterotypic neutralizing antibody titers against the homologous topotype strain were only found after the second immunization, indicating that the phylogenic relationship may differ from the antigenic profiles for these two viruses. The amount of the O1/Campos strain and the revaccination were essential factors for neutralization against the homologous and heterologous type O FMDV viruses. The strain composition of the vaccine was only relevant for cross-neutralization against one of the Asian strains, suggesting potential intra-serotypic divergences for this pattern.

Carnivore protoparvovirus 1 (CPPV-1) is a significant pathogen of domestic carnivores, but its occurrence and genomic diversity in South American wildlife remain poorly characterized. Here we report the first detection and complete-genome characterization of an FPV-like CPPV-1 strain in a Procyon cancrivorus from Northeastern Argentina. Viral DNA was sequenced using tiling-tailed amplicons and NGS (95.4% genomic coverage, mean depth >1700×). Phylogenetic analysis of global genomes indicated that the P. cancrivorus strain clustered robustly within the FPV-like clade and was closely related to FPV variants circulating in domestic cats in Argentina. The CPPV-1 positive individual was clinically healthy, suggesting subclinical spillover at the wildlife-domestic interface. These findings extend the recognized host range of FPV-like parvoviruses in South America and underscore the need for genomic surveillance to monitor cross-species transmission at the wildlife-domestic interface.

This article explores SARS-CoV-2 infection in dogs that have had close contact with humans diagnosed with COVID in Argentina. Affirmative molecular identification of the virus was achieved through RT-PCR analysis of oropharyngeal and rectal swabs from the dog as well as a nasal swab from the guardian. Positive results for the dog were confirmed through a LAMP/CRISPR assay and real time PCR. SARS-CoV-2 genomic RNA was successfully obtained from these samples, and the analysis of a partial sequence of the spike gene (ranging from amino acid 428 to 750) allowed us to classify both genomic sequences as Gamma variants, with a single amino acid variation in position 726. We evaluated the specific humoral immune response of the dog by an indirect ELISA using the Argentinian kit COVID AR IgG ELISA test adapted for domestic dogs, and pseudo-neutralization conducted with SARS-CoV-2 pseudotyped particles. We also evaluated the specific cellular immune response of the dog through a lymphoproliferation assay, using purified spike protein as specific stimulus. This work provides evidence of the human-to-dog transmission of SARS-CoV-2 in Argentina, underscoring the One Health concept and reinforcing surveillance methods in pets.