The H1N1 pandemic is over and the global outbreak turned out to be much less severe than was feared just over a year ago, the head of the World Health Organisation (WHO) said yesterday.
The organisation’s director-general Margaret Chan once again rejected criticism that the United Nations agency had hyped the first pandemic in more than 40 years, whose mildness left some western governments holding huge stockpiles of unused vaccines.
The Hong Kong public health expert said the world had been lucky the H1N1 virus had not mutated into a more deadly form and that a safe vaccine developed in record time remained effective against it. “We are now moving into the post-pandemic period. The new H1N1 virus has largely run its course,” Ms Chan said.
“That was the right call,” she said, defending the decision taken in June last year to declare a pandemic.
The swine flu virus will continue to circulate as part of seasonal influenza for years to come, requiring health authorities to remain vigilant, she told a news conference.
The virus still threatens high-risk groups including pregnant women, who would benefit from vaccination, she said.
Stockpiled H1N1 vaccines remain effective against the strain and so far the virus has not developed widespread resistance to the antiviral oseltamivir, the best treatment, she said. The organisation’s downgrading of the H1N1 outbreak to “post-pandemic” was based on recommendations by external influenza experts.
“I think even if we see severe outbreaks occurring in some countries – which is still definitely possible – that the global threat is really much lower and much different than a year ago,” Keiji Fukuda, the organisation’s top flu expert, told reporters.
In June 2009, the WHO said a new swine flu virus, H1N1, which emerged in the United States and Mexico and spread around the world in six weeks, was the first pandemic since 1968. A full pandemic corresponds to phase six on the WHO’s six-point scale.
“We need to continue to maintain our vigilance and not be complacent,” Ms Chan said, noting that outbreaks continued in countries including India and New Zealand. The behaviour of influenza viruses is notoriously difficult to predict and no two pandemics are alike, flu experts say.
“I am very pleased that European member states prepared for something worse. I’d rather have it go that way than their planning for less or not being prepared at all,” Angus Nicoll, influenza programme co-ordinator at the European Centre for Disease Prevention and Control, said yesterday.
The WHO has also rejected allegations that it acted under the influence of drug companies in declaring a pandemic.
Ms Chan said three viruses were now circulating in many countries as part of a “mixed virus pattern”, typically seen during seasonal epidemics. These were H1N1 and H3N2 – both type A influenza – along with type B.
Some 18,450 people worldwide are confirmed to have died from H1N1 infections, including many pregnant women and young people. But the organisation said it will take at least a year after the pandemic ends to determine the true death toll, which is likely to be much higher.
Seasonal flu kills up to an estimated 500,000 people a year, 90 per cent of them frail elderly people. The 1957 and 1968 pandemics killed about two million and one million people, respectively, the WHO says.