Children aged 18-47 months who had received 2 doses of TIV in a study during the previous season ( primed cohort , n = 192 ) were randomized 1:1 to receive 1 dose of TIV or QIV , and a further 407 children ( unprimed cohort ) were randomized 1:1 to receive 2 doses of TIV or QIV 28 days apart .