Study protocols
PMBL
The study included two site visits: visit 1 (V1) – a screening/randomization visit, before the start of the grass pollen season (22–31 March 2021), visit 2 (V2) – at the peak of the grass pollen season (23 June – 2 July 2021), and two telephone contacts (TC1, TC2; the study protocol registered at Study design. PMBL, polyvalent mechanical bacterial lysate; VAS, visual analogue scale; PNIF, peak nasal inspiratory flow; TNSS, total nasal symptom score.During the visits to the center (V1, V2), blood was taken for immunological tests, the severity of four SAR symptoms was assessed cumulatively on a visual analogue scale (VAS), and peak nasal inspiratory flow (PNIF) was measured using the Youlten Peak Flow Meter (Clement Clarke International, UK) (all subjects received appropriate instructions on how to use the Peak Flow Meter correctly; three measurements were recorded for each subject and the highest flow was used for analysis) (