Genetic immunization of seronegative one-day-old piglets against pseudorabies induces neutralizing antibodies but not protection and is ineffective in piglets from immune dams.
Immune response inhibition by maternal antibodies is a major impediment to the vaccination of the young born to immune dams. This study explored the efficiency of genetic immunization of the neonates at bypassing this inhibition, by testing the muscular inoculation of the gD glycoprotein gene of pseudorabies virus (PRV) in piglets. Plasmid DNA (400 micrograms) was inoculated in four groups of one-day-old piglets, from sows vaccinated or not against PRV. Half of the groups received a booster injection on day 42. All piglets were challenged on day 115. Only piglets from non-immune sows and which received a booster injection developed a medium level of neutralizing antibodies, but they were not significantly protected against the challenge. Piglets from immune sows neither developed an antibody response nor were primed against PRV, as demonstrated by the antibodies kinetics after challenge. It can therefore be concluded that genetic immunization was inefficient at efficiently preventing the immune response inhibition by colostral antibodies.
Monteil
M
M
Unité de génétique moléculaire, génétique virale, Inra, Ecole nationale vétérinaire d'Alfort, Maisons-Alfort, France.
Le Potier
M F
MF
Guillotin
J
J
Cariolet
R
R
Houdayer
C
C
Eloit
M
M
D000818:Animals; D000831:Animals, Newborn; D000914:Antibodies, Viral / Q000096:biosynthesis; D000917:Antibody Formation; D005260:Female; D005814:Genes, Viral; D011558:Herpesvirus 1, Suid / Q000276:immunology*; D006801:Humans; D007112:Immunity, Maternally-Acquired; D007668:Kidney; D051379:Mice; D008815:Mice, Inbred Strains; D010957:Plasmids; D011247:Pregnancy; D011557:Pseudorabies / Q000276:immunology* / Q000517:prevention & control; D022421:Pseudorabies Vaccines; D013552:Swine; D014162:Transfection; D014611:Vaccination / Q000662:veterinary; D014759:Viral Envelope Proteins / Q000096:biosynthesis / Q000235:genetics*; D014765:Viral Vaccines
D000914:Antibodies, Viral; D022421:Pseudorabies Vaccines; D014759:Viral Envelope Proteins; D014765:Viral Vaccines