vulnerable to flu this winter, because so few people caught it last year, because lockdowns meant we mixed less, and we were all washing our hands a lot and being generally more hygienic. our health correspondent, naomi grimley, reports. i've got together some of the country's leading medics to answer your vaccine questions... this is the latest media advert to remind us that it's notjust covid which we have to worry about this winter. flu could rear its head again, too. so more than 40 million people across the uk are being offered a flu jab, in the biggest ever roll—out of the vaccine. those who will be able to get one free include the over—50s, those with certain health conditions, pregnant women, health care workers, and most children. lockdowns and extra hygiene measures squashed flu last winter, and that means the level of immunity in the population is likely to be lower this time round.