Histopathological Pulmonary Lesions in 1st-Day Newborn Piglets Derived from PRRSV-1 MLV Vaccinated Sows at the Last Stage of Gestation
Georgios I. Papakonstantinou,
Dimitra Psalla,
Aris Pourlis,
Ioanna Stylianaki,
Labrini V. Athanasiou,
Eleni Tzika,
Eleftherios Meletis,
Polychronis Kostoulas,
George Maragkakis,
Georgios Christodoulopoulos,
Nikolaos Papaioannou,
Vasileios G. Papatsiros
Affiliations
Georgios I. Papakonstantinou
Clinic of Medicine, Faculty of Veterinary Medicine, School of Health Sciences, University of Thessaly, 43100 Karditsa, Greece
Dimitra Psalla
Laboratory of Pathology, Faculty of Health Sciences, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
Aris Pourlis
Laboratory of Anatomy, Histology & Embryology, Veterinary School, University of Thessaly, 43100 Karditsa, Greece
Ioanna Stylianaki
Laboratory of Pathology, Faculty of Health Sciences, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
Labrini V. Athanasiou
Clinic of Medicine, Faculty of Veterinary Medicine, School of Health Sciences, University of Thessaly, 43100 Karditsa, Greece
Eleni Tzika
Farm Animals Clinic, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54627 Thessaloniki, Greece
Eleftherios Meletis
Laboratory of Epidemiology & Artificial Intelligence, Faculty of Public Health, School of Health Sciences, University of Thessaly, 43100 Karditsa, Greece
Polychronis Kostoulas
Laboratory of Epidemiology & Artificial Intelligence, Faculty of Public Health, School of Health Sciences, University of Thessaly, 43100 Karditsa, Greece
George Maragkakis
Clinic of Medicine, Faculty of Veterinary Medicine, School of Health Sciences, University of Thessaly, 43100 Karditsa, Greece
Georgios Christodoulopoulos
Department of Animal Science, Agricultural University of Athens, 75 Iera Odos Street, Votanikos, 11855 Athens, Greece
Nikolaos Papaioannou
Laboratory of Pathology, Faculty of Health Sciences, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
Vasileios G. Papatsiros
Clinic of Medicine, Faculty of Veterinary Medicine, School of Health Sciences, University of Thessaly, 43100 Karditsa, Greece
Modified live virus (MLV) vaccines for the control of porcine respiratory and reproductive syndrome virus (PRRSV) have been associated with the vertical and horizontal transmission of vaccine viruses. The present study aimed to describe pathological lung lesions in piglets born by gilts vaccinated with PRRSV-1 MLV. In total, 25 gilts were vaccinated at late gestation (100th day) and were divided into five groups according to the different vaccines (Vac) used: no vaccine—control group, Vac-1—strain DV, Vac-2—strain VP-046 BIS, Vac-3—strain 94881, Vac-4—strain 96V198. Within the first 0–9 h of the farrowing, blood samples were collected from all newborn piglets and lung samples were exanimated grossly, histopathologically and with scanning electron microscopy. PRRSV (RT-PCR-positive) and antibodies were detected in the serum of piglets from gilts vaccinated with Vac-2. In these piglets, moderate to severe interstitial pneumonia with thickened alveolar septa was noticed. Type II pneumocyte hyperplasia was also observed. The rest of the trial piglets showed unremarkable lung lesions. Phylogenetic analysis revealed the 98.7% similarity of the PRRSV field strain (GR 2019-1) to the PRRS MLV vaccine strain VP-046 BIS. In conclusion, the Vac-2 PRRSV vaccine strain can act as an infectious strain when vaccination is administrated at late gestation, causing lung lesions.
