IL5 and Recurrent upper respiratory tract infections: Upper respiratory tract infection (URTI) was reported in 19 studies from 17 published articles: Patients (8.57%, 381/4444) in the anti-IL-5 treatment group had similar occurrence of upper respiratory infection to those (9.01%, 377/4183) in the placebo group (RR: 0.93, 95%CI: 0.81–1.07, P = 0.834, I2 = 0.0%), and of 3 sub-treatment groups, patients in the mepolizumab group had relatively less occurrence of upper respiratory infection.