title: Maternally-derived antibodies (MDAs) impair piglets' humoral and cellular immune responses to vaccination against porcine reproductive and respiratory syndrome (PRRS).
abstract: The influence of maternally-derived antibodies (MDAs) on the post-vaccination humoral and cellular immune responses in piglets vaccinated against PRRS was studied. The piglets came from a vaccinated breeding herd. Thirty piglets with a low (A-) or high level (A+) of PRRSV-neutralizing MDAs were vaccinated (V+) with a modified live vaccine at 3 weeks of age. Blood samples were collected before vaccination and then at 2, 4, 8 and 14 weeks post-vaccination (WPV). The samples were analysed to detect the vaccine viraemia (RT-PCR) and quantify the post-vaccination humoral (ELISA and virus neutralisation test) and cellular (ELISPOT IFNγ) immune responses. PRRSV vaccine strain was detected in 60%, 64%, 36% and 0% of A-V+ piglets 2, 4, 8 and 14 WPV respectively. No virus was detected in A+V+ piglets during the first four WPV but 32% and 6% of A+V+ piglets were PCR-positive at 8 and 14 WPV. Eighty-five percent of A-V+ piglets and 0% of A+V+ piglets seroconverted (ELISA) between 2 and 4 WPV. Neutralising antibodies appeared 4 WPV in the A-V+ piglets and 14 WPV in the A+V+ piglets. The number of PRRSV-specific IFNγ-secreting cells was significantly higher in A-V+ piglets at 2 and 4 WPV than in A+V+ piglets. These results show that MDAs can affect both post-vaccination humoral and cellular immune responses in piglets. Further studies are required to assess the impact of MDAs on vaccine efficacy following a PRRSV challenge and its ability to reduce viral transmission.
authors.affiliation: Agence Nationale de Sécurité Sanitaire (ANSES), Unité Epidémiologie et Bien-Etre du Porc, B.P. 53, 22440 Ploufragan, France; Université Bretagne Loire, France. Electronic address: christelle.fablet@anses.fr.
authors.forename: C
authors.initials: C
authors.lastname: Fablet
authors.affiliation: Agence Nationale de Sécurité Sanitaire (ANSES), Unité Virologie Immunologie Porcines, B.P. 53, 22440 Ploufragan, France; Union des Groupements de Producteurs de Viande de Bretagne (UGPVB), 104 rue Eugène Pottier, CS 26553, 35065 Rennes, France; Université Bretagne Loire, France.
authors.forename: P
authors.initials: P
authors.lastname: Renson
authors.affiliation: Agence Nationale de Sécurité Sanitaire (ANSES), Unité Epidémiologie et Bien-Etre du Porc, B.P. 53, 22440 Ploufragan, France; Université Bretagne Loire, France.
authors.forename: F
authors.initials: F
authors.lastname: Eono
authors.affiliation: Agence Nationale de Sécurité Sanitaire (ANSES), Unité Virologie Immunologie Porcines, B.P. 53, 22440 Ploufragan, France; Université Bretagne Loire, France.
authors.forename: S
authors.initials: S
authors.lastname: Mahé
authors.affiliation: Agence Nationale de Sécurité Sanitaire (ANSES), Unité Epidémiologie et Bien-Etre du Porc, B.P. 53, 22440 Ploufragan, France; Université Bretagne Loire, France.
authors.forename: E
authors.initials: E
authors.lastname: Eveno
authors.affiliation: Agence Nationale de Sécurité Sanitaire (ANSES), Unité Virologie Immunologie Porcines, B.P. 53, 22440 Ploufragan, France; Université Bretagne Loire, France.
authors.forename: M
authors.initials: M
authors.lastname: Le Dimna
authors.affiliation: Porc. Spective, Groupe Vétérinaire Chêne Vert Conseil, 56920 Noyal-Pontivy, France.
authors.forename: V
authors.initials: V
authors.lastname: Normand
authors.affiliation: Porc. Spective, Groupe Vétérinaire Chêne Vert Conseil, 56920 Noyal-Pontivy, France.
authors.forename: A
authors.initials: A
authors.lastname: Lebret
authors.affiliation: Agence Nationale de Sécurité Sanitaire (ANSES), Unité Epidémiologie et Bien-Etre du Porc, B.P. 53, 22440 Ploufragan, France; Université Bretagne Loire, France.
authors.forename: N
authors.initials: N
authors.lastname: Rose
authors.affiliation: Agence Nationale de Sécurité Sanitaire (ANSES), Unité Virologie Immunologie Porcines, B.P. 53, 22440 Ploufragan, France; Université Bretagne Loire, France.
authors.forename: O
authors.initials: O
authors.lastname: Bourry
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D000917:Antibody Formation / Q000276:immunology; D007112:Immunity, Maternally-Acquired; D019318:Porcine Reproductive and Respiratory Syndrome / Q000517:prevention & control*; D013552:Swine; D014611:Vaccination; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D014765:Viral Vaccines
keywords: Immune response; Maternal neutralizing antibody; PRRS; Vaccination