A committee of experts has informed the World Health Organization on Tuesday that the pandemic of H1N1 swine flu has not yet worn out.

"The committee advised that it was premature to conclude that all parts of the world have experienced peak transmission of the H1N1 pandemic influenza and that additional time and information was needed to provide expert advice on the status of the pandemic", said WHO spokesman Gregory Hartl by an e-mail.

A news conference has been planned for Wednesday by WHO. The emergency committee, composed of 15 experts and headed by Australian John MacKenzie, makes off the record recommendations to WHO director-general Dr. Margaret Chan. Then she has to inform the health ministries of WHO's 192 member states. WHO's top flu expert Dr. Keiji Fukuda will announce its decision formally on Wednesday at 1000 GMT.

An experiment on mice proved that a single gene segment from a human seasonal flu virus, H3N2, is capable of converting the avian H5N1 virus into a highly pathogenic form.

"H5N1 virus has never acquired the ability to transmit among humans, which is why we haven't had a pandemic. The worry is that the pandemic H1N1 virus may provide that nature in the background of this highly pathogenic H5N1 virus", said Kawaoka, a professor of pathobiological sciences at the UW-Madison School of Veterinary Medicine.