An English school today became the 20th to close since the outbreak of swine flu.
The Health Protection Agency said five schools were currently closed and 15 have shut and since reopened.
The junior school in Berkshire closed after a pupil contracted the virus on a trip to America.
Berkshire West NHS said the infected child was making "good recovery".
Emmbrook Junior School in Wokingham was open until noon today so children and staff could receive antiviral inoculations but will be closed for a week.
"We had a team of doctors and other clinicians at the school throughout the morning checking all children for symptoms," said NHS Berkshire West consultant in Public health Dr Jane Wells.
"All children and staff were offered antiviral medication as a preventative measure and advised to remain at home for seven days."
Emmbrook Junior School head teacher Paul Rowe said: "We are working closely with Health Protection Agency and on their advice the school will reopen on Tuesday June 16.
"This is to reduce the impact of the possible spread of the infection."
Among the 20 closed education establishments was public school Eton College which had to shut for a week because 31 students and staff were infected with the influenza virus.
A further nine people in England were confirmed with swine flu today, bringing the total in the UK to 675, health officials said.
There have now been 435 confirmed cases in England, 232 in Scotland, six in Northern Ireland and two in Wales, according to the Health Protection Agency.
Another 504 possible cases are under investigation.