Can an experimental PCV2d virus-like-particle vaccine protect pigs?
In an experimental trial involving ten SPF miniature pigs, a PCV2d virus-like-particle vaccine markedly reduced viral detection after challenge, but farm effectiveness remains unproven.
In an experimental trial involving ten SPF miniature pigs, a PCV2d virus-like-particle vaccine markedly reduced viral detection after challenge, but farm effectiveness remains unproven.
Problem: PCV2d currently predominates in many regions, creating interest in recombinant vaccines based directly on this genotype.
Methods: Ten three-week-old SPF miniature pigs were allocated to vaccinated (n=5), challenged control (n=3), and unchallenged control (n=2) groups. The vaccinated and challenged-control groups were exposed to PCV2d four weeks after vaccination.
1. Vaccination generated neutralizing antibodies to PCV2b and PCV2d plus an IFN-γ response, with a stronger immune response than in challenged controls before exposure.
2. After challenge, PCV2d DNA was nearly absent from serum, swabs, and tissues of vaccinated animals, whereas challenged controls developed viremia, shedding, and PCV2-associated lesions.
3. The findings are promising but come from only ten SPF miniature pigs under experimental conditions and therefore do not yet demonstrate commercial-farm effectiveness.
Original publication
Kim K, Choi K, Shin M, Hahn T-W. A porcine circovirus type 2d-based virus-like particle vaccine induces humoral and cellular immune responses and effectively protects pigs against PCV2d challenge. Frontiers in Microbiology. 2024;14:1334968.