Schools should be closed to help reduce the number of swine flu cases, ministers have been told.
Scientists from Imperial College London said that "prolonged" school closures could reduce the number of infections by up to 45 per cent.
The advice comes amid fears that transmission of the virus will have significantly increased by the end of the school holidays.
In a paper published in the Lancet medical journal, Professor Neil Ferguson and Dr Simon Cauchemez said that a school closure programme could buy time to produce a vaccine.
"It is... hoped that closure of schools during the pandemic might break the chains of transmission, with the following potential benefits: reducing the total number of cases; slowing the epidemic to give more time for vaccine production; and reducing the incidence of cases at the peak of the epidemic, limiting both the stress on healthcare systems and peak absenteeism in the general population, and thus increasing community-wide resilience," they wrote.
The scientists quoted a recent French study which suggested that closing schools could reduce the number of cases by 13 to 17 per cent overall, and by between 38 and 45 per cent during the most infectious period.
Children between the ages of five and fourteen have so far appeared to be more susceptible to the virus than adults, they said.
But the Schools Secretary, Ed Balls, said that there was "no longer" a strong argument for closing schools because the virus was already established in the community.
He added: "We will be monitoring the situation closely over the school holidays and will review the evidence in late August."
In a statement to MPs on Monday, the Health Secretary, Andy Burnham, said a new national flu service would be launched later this week to reduce the burden on GPs.
The National Pandemic Flu Service will allow people to receive a diagnosis and obtain antiviral drugs over the internet and the telephone.
He rejected claims by opposition parties that government in-fighting had delayed the launch of the hotline, arguing that ministers did not want to act until the health service was under intense pressure.
He also denied that guidance to pregnant women had been confused and inconsistent.
The NHS website currently advises expectant mothers to avoid rush-hour trains and buses in order to minimise contact with crowds, but a statement from officials at the weekend said that daily routine should continue where possible.
Burnham said that the official advice was that women should avoid crowds where reasonably possible. He added that people should not significantly alter their daily routines or stay at home from work.
29 people have now died in the UK as a result of the virus, 26 in England and three in Scotland. Health officials have warned that as many as 65,000 people could die from swine flu this winter.
