The Government has warned of a “second wave” of swine flu after the current outbreak dies out.
Health Secretary Alan Johnson said the deadly H1N1 virus is being contained effectively but there could be a “much more serious” pandemic in the autumn or winter.
He spoke after three more cases of swine flu were confirmed by the Department of Health, bringing the total number of victims in the UK to 18.
A 14-year-old girl from Barnet, north London, was found to have the virus following contact with a visitor to a Mexico and an 11-year-old child in Wandsworth, south London, tested positive following a visit to the US. The third victim is a man from Ayrshire, Scotland.
Mr Johnson said: “At the moment all the evidence is we can confine it, contain it and treat it effectively.”
But he added: “Our evidence from all previous pandemics is you get two phases. So you get a first wave which is often very mild and then you get a much more serious wave that comes along in the autumn and the winter.”