Quadrivalent live attenuated influenza vaccine (LAIV4) has been found effective and safe in children aged more than 4 years by not contributing to asthma exacerbations, according to data from a randomised control trial published in Pediatrics. The study analysed 151 children with persistent asthma aged between 5 and 17 years over the course of two influenza seasons to find that 18 children out of the cohort experienced an asthma exacerbation — eight in the LAIV4 group and 10 in the quadrivalent IIV (IIV4) group. There were no significant differences in the frequency of asthma symptoms, change in [peak expiratory flow rate], or childhood asthma control test/asthma control test scores in the 14 days post vaccination between LAIV4 and IIV4 recipients, the researchers wrote.