Figure 2. Frequency of Recurrences .

Frequency of recurrences (A) before and after vaccination in patients with recurrent disease (n = 26) and (B) after vaccination in patients newly diagnosed with recurrent respiratory papillomatosis (n = 11) and those with recurrent disease (n = 26). Horizontal lines in the boxes represent the median and quartiles, and whiskers are given by the maximal (minimal) value that is not considered as an outlier, ie, not more than 1.5 times IQR distant from the box.