title: Influence of age on the effectiveness of PCV2 vaccination in piglets with high levels of maternally derived antibodies.
abstract: Two field studies were conducted to investigate the influence of age on the efficacy of vaccination against Porcine Circovirus Diseases (PCVD) in animals with high levels of maternally derived antibodies (MDA). A total of 416 piglets (Study 1) and 600 piglets (Study 2) were randomly allocated to one of three groups. Two groups in each study received a single dose of a PCV2 subunit vaccine, one group at 1 week old and the other at 3 weeks of age. The third group was left untreated. Animals vaccinated at 3 weeks of age showed a significantly higher average daily weight gain and significantly reduced viraemia following PCV2 infection than the respective control groups. This difference was not observed in pigs vaccinated at 1 week of age. Furthermore, only animals vaccinated at 3 weeks of age showed an increased serological response and a higher frequency of IgM-positive animals compared with controls. The data indicated that PCV2 vaccination in the presence of high MDA levels is efficacious when used in 3-week old but not in 1-week old pigs. As the range of MDA titres of pigs vaccinated at both 1 and 3 weeks of age were comparable, the data suggest that PCV2 vaccine efficacy was independent of the level of MDA. It appears that other age-related factors affecting the active and passive transfer of immunity may perhaps have interfered with the efficacy of the vaccine in 1-week old piglets. These findings have implications for future PCV2 vaccine testing and administration strategies.
authors: Clinic for Swine, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria.
authors: Michael
authors: M
authors: Haake
authors: Clinic for Swine, Ludwig-Maximilians-University, Sonnenstr. 16, 85764 Oberschleißheim, Germany.
authors: Andreas
authors: A
authors: Palzer
authors: Clinic for Swine, Ludwig-Maximilians-University, Sonnenstr. 16, 85764 Oberschleißheim, Germany.
authors: Beate
authors: B
authors: Rist
authors: Institute of Pathology and Forensic Veterinary Medicine, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria.
authors: Christiane
authors: C
authors: Weissenbacher-Lang
authors: MSD Animal Health, Wim de Körverstraat 35, 5830 AA Boxmeer, The Netherlands. Electronic address: Vicky.Fachinger@merck.com.
authors: Vicky
authors: V
authors: Fachinger
authors: MSD Animal Health, Wim de Körverstraat 35, 5830 AA Boxmeer, The Netherlands.
authors: Alex
authors: A
authors: Eggen
authors: Clinic for Swine, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria; Clinic for Swine, Ludwig-Maximilians-University, Sonnenstr. 16, 85764 Oberschleißheim, Germany.
authors: Mathias
authors: M
authors: Ritzmann
authors: Clinic for Swine, Ludwig-Maximilians-University, Sonnenstr. 16, 85764 Oberschleißheim, Germany.
authors: Matthias
authors: M
authors: Eddicks
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology; D018173:Circoviridae Infections / Q000517:prevention & control / Q000662:veterinary*; D017925:Circovirus / Q000276:immunology*; D005260:Female; D007112:Immunity, Maternally-Acquired / Q000276:immunology*; D008297:Male; D011897:Random Allocation; D034421:Sus scrofa; D013552:Swine; D013553:Swine Diseases / Q000276:immunology / Q000517:prevention & control* / Q000821:virology*; D022223:Vaccines, Subunit / Q000008:administration & dosage / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage* / Q000276:immunology; D014766:Viremia / Q000517:prevention & control / Q000662:veterinary
chemical_list: D000914:Antibodies, Viral; D022223:Vaccines, Subunit; D014765:Viral Vaccines
keywords: Animal health; MDA; Neonate; PCV2; Swine; Vaccine