Parents are being urged to remain vigilant over the threat of flu amid an expected rise in new cases as people return to work and school following the Christmas holidays.
Health experts also stressed that it was not too late for members of "at risk" groups, including those with chronic respiratory problems, to be vaccinated against flu, which has been linked to 39 deaths in Britain since October.
Professor John Oxford, an expert in virology at St Bartholomew's and the Royal London Hospital, said the return of children to school had in the past prompted a rise in the number of flu cases.
"You tend to get a surge," he said. "I would anticipate a surge, but how long that will last is difficult to say."
Recommending that parents of children in high-risk groups should have them vaccinated as soon as possible, Prof Oxford added: "This virus is not going to go away next week. Even if it's already peaked, it's still going to be around for the next couple of weeks and it's still worthwhile being vaccinated at this stage."
Parents had no need to panic but should adopt a disciplined approach to curbing the spread of flu, said the expert, who advised them to keep children away from school if they showed signs of flu.
Although closing schools in response to flu pandemics had not proved effective, Prof Oxford said parents were far from "powerless" and could aid the fight against the virus by ensuring good hand hygiene and keeping children away from others with the illness where possible.
Dr Douglas Fleming, director of the Royal College of General Practitioners' Research and Surveillance Centre, also voiced concern that the current flu outbreak may not have peaked despite the fact that a large number of children had already had the virus.
"This is a H1 virus and we know that spreads rapidly amongst children," Dr Fleming noted. "I personally don't feel that we have quite reached the peak."
The Government relaunched its national flu prevention campaign on New Year's Day in an attempt to quell the rising number of people being diagnosed with the illness.