showed a trendp < 0.0001
The A/California strain showed a trend characterized by two different peaks: the first in 2010/2011 (49.0%, 95% CI 39.0–59.0; p < 0.0001 vs. 2009/2010 for HI results) and the second one in 2014/2015 (53.0%, 95% CI 43.0–62.0; p = 0.004 vs. 2013/2014 for HI results).