Monitoring
The change in vaccination composition and timing was accompanied by a protocol (Figure 2) which included monitoring for influenza virus A by RRT-PCR testing in the breeding herd and in both suckling piglets and nursery pigs
Summary of the sampling protocol and vaccination timeline in a 1200-sow farm undergoing a respiratory disease outbreak in suckling piglets. An inactivated commercial vaccine was administered to the entire breeding herd (lactating, gestating, and open sows, and gilts) in 1 day during week 6 of 2011 (red arrow). A second dose was administered 5 weeks later: lactating, gestating, and open sows were vaccinated on the same day and gilts 3 days later (blue arrow). Nasal swabs and blood samples were collected from lactating and gestating females 1 week before the first vaccination and 3 weeks after the second vaccination. Suckling-piglet samples were collected 3 weeks after the first vaccination and then every other week (seven occasions total). Samples were collected from one nursery cohort on the sixth week of the year and then every other week during the nursery phase. A second nursery cohort was monitored in the same manner starting on week 16 of the year.