Reduction in heterologous challenge virus replication in vaccinated birds.

<p>At 5 weeks of age (5 wpv for 1d IIV and 1d LAIV; 2 wpv for 3w LAIV and 3w IIV), chickens were challenged with heterologous virus and tracheal swabs were taken at 2 and 4 days post challenge to determine the level of challenge virus replication. Each swab was eluted in 2 ml of PBS. Virus titers are expressed as median egg infectious doses per ml of tracheal swab eluate. (A) 2 days post-challenge. (B) 4 days post-challenge. Groups are arranged as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0195285#pone.0195285.g005" target="_blank">Fig 5</a>. Different letters inside the plot indicate significant differences between groups (p<0.05).