U. S. experts said on Wednesday that "people who were morbidly obese and school-aged children were much more likely to become seriously ill or to die from H1N1 swine flu".

Experts at the U. S. Centers for Disease Control and Prevention said, "Preliminary data indicated that the morbidly obese had four times the rate of hospitalizations and deaths, while the death rate for children was five times higher than usual".

CDC's Dr. Nancy Cox, Dr. Anne Schuchat and Dr. Lyn Finelli told a meeting of the Advisory Committee on Immunization Practices that they are working up detailed studies of the pandemic in the United States.

Schuchat said in the meeting, "We estimate that the deaths in children are probably fivefold higher, at least, than what is usually seen in seasonal flu".

"Deaths among the elderly were about five times less than in a usual flu season", added Schuchat.

In related news, the World Health Organization said on Wednesday that "it was too early to say the pandemic had peaked globally, although it has clearly waned in North America and Europe".

Dr. Nancy Cox said that the pandemic version of H1N1 had "clearly replaced its distant cousin, seasonal H1N1, this year".

But Cox further elaborated, saying "it is too soon to say H1N1 is just one of several circulating seasonal influenza strains".