Vol 215, Issue 11: 22 November 2021. Associate Professor Sheena Sullivan is Head of Epidemiology at the WHO Collaborating Centre for Reference and Research on Influenza, at the Peter Doherty Institute. She talks about the impact of opening the international borders on influenza cases and severity this coming summer. To accompany her editorial at https://www.mja.com.au/journal/2021/216/1/preparing-out-season-influenza-epidemics-when-international-travel-resumes, and research by Marsh et al, at https://www.mja.com.au/journal/2021/216/1/drivers-summer-influenza-epidemic-new-south-wales-2018-19 ... with MJA news and online editor, Cate Swannell. 16 mins, 22 secs.