Study links sow vaccine timing to piglet immunity in CSF
A new Frontiers in Veterinary Science study suggests that both vaccine platform and gestational timing can materially shape passive immunity against classical swine fever in newborn piglets. Researchers from IRTA-CReSA in Spain, the Colombian Agricultural Institute, and the USDA’s Plum Island Animal Disease Center compared maternal vaccination with the traditional live attenuated C-strain vaccine and the recombinant, DIVA-compatible FlagT4G vaccine during pregnancy. In sows vaccinated at 72 days of gestation, both vaccines generated E2-binding antibodies, but FlagT4G produced stronger, broader neutralizing responses in both sows and piglets. Piglets from C-strain-vaccinated sows showed ELISA-detectable antibodies, yet neutralizing activity was lower and waned faster. The same paper also found that vaccinating sows with FlagT4G earlier, at 44 days of gestation, yielded strong maternal antibody transfer without detectable vaccine RNA in piglets at birth. (frontiersin.org)
Why it matters: For veterinary professionals working in swine health, the findings add nuance to how maternal vaccination programs may be designed in endemic settings. The study points to a difference between antibody detection and functional neutralization, which matters when assessing whether piglets are likely to be protected. It also highlights a practical diagnostic issue: after sow vaccination at 72 days of gestation, low-level vaccine-derived CSFV RNA was detected transiently in some piglets, without clinical disease, meaning PCR results in vaccinated herds may need careful interpretation. That’s especially relevant because classical swine fever control still relies heavily on vaccination in endemic regions, while DIVA-compatible tools remain important for surveillance and eradication-oriented programs. (frontiersin.org)
What to watch: Watch for follow-up work on whether these results hold in larger field studies, and how they influence sow vaccination timing, piglet vaccination windows around weaning, and diagnostic protocols in vaccinated herds. (frontiersin.org)