Schools may have to close if bird flu arrives in the UK, the Department of Health has said.
So far, 58 people have died from the disease in south Asia - about half of those infected.
Bird flu is caught from infected birds, but there is concern that the virus could mutate to pass from person to person. Symptoms range from conjunctivitis to fever and severe aching which can lead to pneumonia.
The Government's pandemic contingency plan, published in March, says one in four of the UK population could be affected and the number of deaths could be 50,000 or higher.
It says: "Influenza will spread rapidly in schools. In 1957, for example, up to 50 per cent of schoolchildren developed influenza, but even those schools which were most severely disrupted had returned to normal four weeks after the appearance of the first case.
"In residential schools, attack rates reached 90 per cent, often affecting the whole school within a fortnight."
The Government has ordered 14.6 million doses of antiviral drugs for bird flu. And the Department of Health said local education authorities will be advised about closing schools.
The influenza pandemic of 1918 to 1919, caused an estimated 40 to 50 million deaths worldwide - about five times more than the First World War.