Background: Torovirus infections have been associated with gastroenteritis and diarrhea in horses, cows, pigs and humans, especially in young animals and in children. Although asymptomatic in a large percentage of cases, however toroviruses may pose a potential threat to worsen disease outcome in concurrent infections with other enteric pathogens. Previous studies based on the analysis of limited numbers of samples indicated high seroprevalences against porcine torovirus (PToV) in various European countries. The aim of this work was to perform a seroepidemiological survey of PToV in Spanish farms in order to define the seroprevalence against this virus. Results: Serum samples (n = 2664) from pigs of different ages were collected from 100 Spanish farms coming from 10 regions that concentrate 96.1% of the 3392 farms with 80 or more sows censused in Spain. Samples were screened by means of an indirect enzyme-linked immune-sorbent assay (ELISA) based on a recombinant PToV nucleocapsid protein as antigen. The analysis of the whole serum collection yielded a total of 95.7% (2550/2664) seropositive samples. The highest prevalence (99.6%, 1382/1388) and ELISA values (average O.D. ± standard deviation) were observed in the sows (1.03±0.36) and the lowest prevalence (59.4%, 98/165) and anti-PToV IgG levels (0.45±0.16) were found amongst 3-week-old piglets. Both ELISA reactivity values and seroprevalence percentages rose quickly with piglet’s age from 3 to 11 weeks of age; the seroprevalence was 99.3% (2254/2270) when only the samples from sows and pigs over 11-weeks of age were considered. Antibodies against PToV were detected in all analyzed farms. Conclusions: This report describes the results of the largest torovirus seroepidemiological survey in farmed swine performed so far. Overall, the seroprevalence against PToV in animals older than 11 weeks of age was >99%, indicating that this virus is endemic in pig herds from Spain.

Objective: The efficacy of Vepured, a recombinant verotoxin 2e (VT2e) vaccine, against clinical signs and mortality of VT2e-induced toxemia was evaluated in a controlled experimental challenge. Materials and methods: Piglets free of VT2e neutralizing antibodies (NAb) were selected and blocked by weight and litter and randomly allocated between three groups: vaccinated (n = 32); non-vaccinated (n = 32); and non-vaccinated, non-challenged (n = 10). Piglets were vaccinated intramuscularly with 1 mL of Vepured (vaccinated) or phosphate-buffered saline (non-vaccinated) at two days of age. The onset and duration of protection were investigated via intravenous VT2e challenge, using mortality and clinical signs related to VT2e-induced toxemia. Results: Mortality in the non-vaccinated piglets was 92.3% and 68.8% at the onset of immunity and through the experiment duration, respectively, whereas all vaccinated piglets survived the challenge. The total clinical score and percentage of animals with clinical signs were greater (P < .05) in the non-vaccinated group. Also, vaccinated pigs had better growth performance than non-vaccinated pigs. Neutralizing antibodies against VT2e were detected in most (78.6%) vaccinated piglets at 21 days and in all vaccinated piglets at 28 days and mean NAb titers (log2) were 3.9 and 4.3, respectively. Moreover, NAb persisted for at least 112 days in most (94.1%) vaccinated animals (mean NAb titer was 3.8). Implications: In this study, active immunization with Vepured conferred effective protection against VT2e-induced toxemia, reducing the presence and severity of clinical signs and preventing mortality related to VT2e-induced toxemia from 21 to 112 days after vaccination.

Mycoplasma hyopneumoniae (Mhyo) and porcine circovirus type 2 (PCV2) infections cause enormous economic losses in the swine production sector. Vaccination remains the most effective strategy against the complex clinical entities caused by these pathogens. While effective vaccines against PCV2 are available, immunisation against Mhyo continues to be challenging. In parallel, intradermal (ID) vaccination can optimise time and costs while providing faster and user-safe administration. This study compares the safety and efficacy of commercial porcine vaccines against Mhyo and PCV2, including intramuscular (IM) and ID ones: (1) ID recombinant Mhyo-PCV2, (2) ID recombinant PCV2 + ID inactivated Mhyo, (3) IM bivalent inactivated Mhyo and recombinant PCV2, (4) IM bivalent inactivated Mhyo and inactivated chimeric PCV1-PCV2 and (5) IM inactivated Mhyo + IM inactivated PCV2. Safety, evaluated through clinical signs, adverse effects, local reactions, and average daily weight gain, has been confirmed for all vaccines. Following challenge with both pathogens, all products reduced PCV2 viremia and faecal shedding, proving efficacy against PCV2 infection. In contrast, only the ID recombinant Mhyo-PCV2 and the IM inactivated Mhyo + IM inactivated PCV2 vaccines, significantly reduced lung lesions related to Mhyo infection, indicating a better protection compared to the other vaccines.

Vaccination is essential for disease prevention in swine production; however, repeated intramuscular (IM) injections can compromise animal welfare. This st