Health chiefs have warned that it is "virtually impossible" to accurately predict when a second wave of swine flu will hit the UK.
Chief Medical Officer Sir Liam Donaldson admitted that the government was expecting the number of cases to rise in autumn when schools and colleges get back to session but it was difficult to predict any accurate timing.
Figures released show a decline in the number of newly-diagnosed swine flu cases, with an estimated 11,000 new cases in England last week compared to 25,000 for the week before.
The number of patients being treated in English hospitals has come down from 371 to 263 during the period.
So far 54 people have died from the disease, up from 44 last week, with 25 of these in the capital. Five additional deaths were reported in Scotland over the week.
The National Pandemic Flu Service reports the highest levels of activity on Mondays.