* Officials describe worry about H1N1 threat when it emerged
* WHO chief rejects claims of industry influence
By Laura MacInnis
GENEVA, Sept 28 (Reuters) - The World Health Organisation did not hype the risks of H1N1 flu, and made the best decisions possible with the information available about the new virus, WHO Director-General Margaret Chan said on Tuesday.
Addressing an external review panel, Chan defended the steps she took from finding out about the strain to declaring it a pandemic, a move that set in motion global vaccination campaigns that were later criticised as unnecessary.
"I personally do not believe that WHO exaggerated the threat," she told the experts at her U.N. agency's headquarters, describing a decision to err on the side of caution about the bug that eventually caused only mild illness in most people.
"A new disease is, by definition, poorly understood as it emerges," the former Hong Kong health director, who formerly battled the spread of SARS and avian flu, said, describing an "atmosphere of uncertainty" at the onset of the pandemic.
"We are grateful for the moderate impact (of H1N1). Had the virus turned more lethal, we would be under scrutiny for having failed to protect large numbers of people."
After the H1N1 strain was identified in Mexico, where it caused deadly pneumonia in pregnant women and seemingly healthy young people, and was also found in the United States, the WHO activated its pandemic alert scale, fearing the disease could kill as many as millions of people as it swept the world.
At least 18,450 people worldwide are confirmed to have died from H1N1 infections, but the WHO says it could take another year to determine the true death toll. Seasonal flu kills an estimated 500,000 people every year, most of them elderly.
Keiji Fukuda, the WHO's top flu expert, has admitted the six-point pandemic alert scale caused undue confusion as the virus spread in a seemingly milder form. [ID:nLDE63B1BG]
But he told the review panel that when H1N1 first emerged, concerns about the victims suffering extreme symptoms and death dominated the international response, leading to extra heed.
"The initial cases were occurring in a very young and healthy group," he explained. "This was something that really set the concerns about how things would progress."
As the strain spread worldwide, vaccine makers such as Sanofi-Aventis (SASY.PA), GlaxoSmithKline (GSK.L), Novartis NOVN.VX and AstraZeneca (AZN.L) worked to create immunisations to match virus samples from affected countries.
But the H1N1 strain appeared to actually cause less death and serious disease than normal seasonal influenza does, leading many critics to question whether the large-scale vaccinations served mainly to line the pockets of pharmaceutical companies.
Chan rejected this outright.
"Never for one moment did I see a single shred of evidence that pharmaceutical interests, as opposed to public health concerns, influenced any decisions or advice provided to WHO by its scientific advisers," she said. "Never did I see a shred of evidence that financial profits for industry, as opposed to epidemiological and virological data, influenced WHO decisions."
The director-general decided to declare a full pandemic in June 2009 following guidance from an emergency committee whose make-up was kept anonymous until after the pandemic was declared over last month. [ID:nLDE6790D9]
That anonymity, Chan said, ensured the experts were shielded from "political, commercial and media" interests.
She also said the international response to H1N1, including efforts to stockpile and donate drugs to poorer countries, was helpful and had raised awareness about the global nature of health threats that could help in future emergencies.
The external panel, formerly called the International Health Regulations Review Committee, will prepare a report on the WHO's handling of the flu pandemic for consideration by the U.N. agency's 193 member states next year.