Clinical study NAIB2008. Median viral titer versus day of study is shown. ⧫, placebo (n = 14); ▴, IH plus IN zanamivir BID (n = 13); ●, IH plus IN zanamivir QID (n = 13). P = 0.005, BID versus placebo; P = 0.021, QID versus placebo, by AUC analysis. Limit of detection, 1.5 log10 TCID50s/ml.