Vaccination is the cornerstone of control of Influenza A Virus (IAV) in swine populations. The control of IAV in the growing pig population starts with control in the breeding herd. University of Minnesota researchers wanted to assess the effect of sow vaccination on IAV infection in pigs at weaning in a cohort of 52 breeding herds. The herds were voluntarily enrolled according to their IAV history, sow vaccination protocol and monitored during a six month period as a prospective longitudinal study. On each herd, nasal swabs were collected monthly from 30 pigs at weaning and tested for IAV by RT-PCR.
The researchers found the following:
- IAV was detected in 25% (75/305) of the monthly sampling events
- IAV was detected in 15% (458/3050) of pools that were tested.
- There were 9,150 individual nasal swabs that were subsequently pooled with 3 individual nasal swabs/pool.
- IAV infections in pigs at weaning were lower in vaccinated herds compared to non-vaccinated herds
- There was no significant difference between prefarrow and whole herd vaccination protocols. Prefarrow and whole herd vaccination protocols reduced the odds of groups testing IAV positive at weaning in comparison with no vaccination
Take Home Message
- These results demonstrated that sow herd vaccination is a useful strategy for control of influenza infections in pigs at weaning.
- It is interesting that both the prefarrowing booster approach and the blitz whole herd vaccination approach were effective in controlling the rate of infection in weaned pigs.
Submitted by Kevin Vilaca, DVM
Ref: Fabian O Chamba Pardo , Matthew W Allerson , Marie R Culhane, Robert B Morrison , Peter R Davies , Andres Perez, Montserrat Torremorell Effect of influenza A virus sow vaccination on infection in pigs at weaning: A prospective longitudinal study Transbound Emerg Dis . 2020 Jul 11. doi: 10.1111/tbed.13688.