Director-General of the World Health Organization Margaret Chan, MD, MPH, has declared an end to the H1N1 influenza pandemic, following the advice of an emergency committee convened to address the issue.

"The new H1N1 virus has largely run its course," she said from Hong Kong in a conference call with reporters.

Based on previous pandemics, Chan said the virus is expected to behave like seasonal influenza viruses and continue to circulate "for some years to come." It also will likely continue to cause serious disease in younger individuals, at least in the immediate post-pandemic period, she said.

Chan noted that significant localized outbreaks of H1N1 were still possible, as is currently occurring in New Zealand.

Because of the continuing threat, the WHO continues to recommend immunization with both the monovalent H1N1 vaccine and the trivalent seasonal vaccine, of which the new H1N1 virus is a component.

The decision to declare an end to the pandemic was made based on several factors, according to Chan: the lack of out-of-season — or summer — outbreaks in either the Northern or Southern Hemisphere, the fact that current H1N1 outbreaks are similar in intensity to those of seasonal influenza, and the increasing mix of circulating influenza viruses.

Source: MedPage Today