Warning to parents that toddlers are 'superspreaders' of flu The vaccine began being offered to toddlers last winter. But new figures show that so far, uptake has been much lower than last year, with just 28.5 per cent of 2-year-olds receiving it, compared with 34.1 per cent this time last year. Uptake among 3-year-olds is also slightly lower this year, at 30.5 per cent. Dame Sally urged parents to get children vaccinated, to stop the virus sweeping through families. She said: "Flu can be really nasty for toddlers, leading to time off nursery which has a big impact on mums and dads and sometimes even a stay in hospital. They also spread the virus easily and often pass flu to grandparents and other relatives who can become very ill, fast. She said it was in everyone's interests to protect young children to "help avoid a miserable winter for all the family." Young children are most likely to spread flu because they tend to have greater contact with others, and may not cover their mouths when coughing and sneezing or wash their hands enough. Officials said forecasts show that if half of children under the age of four had the vaccine almost half a million cases of flu would be prevented. Pregnant women, under 65s with long-term health conditions and pensioners are all eligible for free flu vaccinations on the NHS. The flu season runs from November to March. Health officials said it was important to be vaccinated before the virus begins to circulate widely. They said the nasal spray vaccine offers the best protection for children and the only likely side effect is a slight runny nose for a short time. Last year the vaccine was introduced for free on the NHS in England for two and three-year-olds. This year it was extended to four-year-olds and the aim is to gradually roll it out to all two to 16 year olds.