All children are to be given the flu vaccination after experts said it could save up to 2,000 lives a year.
The scheme, which is expected to be rolled out in 2014, will see all children aged two to 17 given the vaccination through a nasal spray. Younger children will be given the spray at their GP practice and schoolchildren will receive it at school.
The Joint Committee on Vaccination and Immunisation, which advises the Government on vaccination policy, said the flu programme should be extended to children because it could reduce the rate of infection by 40%.
Health Secretary Andrew Lansley has accepted the recommendation, a Department of Health spokesman said. At present, over-65s, pregnant women and people with a serious medical condition, including children, are eligible for a seasonal flu jab.
The UK will become the first country to offer the flu vaccine to healthy children free of charge. The measure is expected to cost £100 million a year.
Healthy children are among those who are least likely to develop complications from being infected by flu, but their close contact with each other means they are more likely to transmit the virus to one another and other vulnerable people.
The mass immunisation programme is estimated to lead to 11,000 fewer hospital admissions and 2,000 fewer deaths every year.
Chief medical officer Professor Dame Sally Davies said: "We accept the advice of our expert committee that rolling out a wider programme could further protect children, with even a modest take-up helping to protect our most vulnerable.
"There are significant challenges to delivering a programme that requires up to nine million children to be vaccinated during a six-week period and we will look at the recommendations in detail to decide how best to develop and deliver the programme."
Professor Adam Finn, professor of paediatrics at the University of Bristol, said: "I think vaccination of healthy schoolchildren with the new nasal flu vaccine is a good idea as we know it's effective and safe and flu can be a serious illness in childhood, not just in old age. There should be time to do some more research before we introduce the vaccine to help us predict how well such a programme would be accepted and would work."