Swine Flu Fizzles Out; WHO May Declare End to Pandemic Alert

Public health experts are likely to tell the world this month it can breathe easier: The swine flu pandemic is ending.

The World Health Organization’s emergency committee may convene next week to review infection data from Argentina to New Zealand and recommend that the agency declare the century’s first flu pandemic to be over, said two people familiar with the matter. They declined to be identified because the deliberations are confidential.

WHO Director-General Margaret Chan has to decide whether the virus warrants extra vigilance as it circles the globe a second time with no sign it’s becoming deadlier or developing resistance to Roche Holding AG’s Tamiflu drug. More than $14 billion was spent on vaccines and medicines to fight the germ, which shared features of the Spanish flu of 1918 while causing little more than a fever and a cough in a majority of patients.

“We have to count our lucky stars,” said Malik Peiris, professor of microbiology at Hong Kong University, in a telephone interview. “We were really fortunate that on this occasion it was a very mild infection.”

A decision by Chan to scale down the pandemic response will be guided by how the virus evolves and a date for an announcement hasn’t been set, said Gregory Hartl, a WHO spokesman.

‘Very Watchful’

The emergency panel was to convene as early as today, the two people said. The WHO late yesterday decided it may take a little longer to review the latest flu data and allow Argentina to wrap up its vaccination campaign, one of the people said.

The WHO moved to the top level of its six-step pandemic alert in June 2009 after the discovery of the new H1N1 virus in Mexico and the U.S. two months earlier, sparking what the agency described as a health emergency of international concern. The virus is now circulating at low levels worldwide after killing at least 18,337 people, WHO said on July 16.

“We are still not at the end of the Southern Hemisphere flu season, so we have to be very watchful,” Hartl said yesterday by telephone from WHO’s headquarters in Geneva.

U.S. health authorities determined last month that special medical measures to fight the first flu pandemic in 41 years are no longer required and said other countries are likely to make similar assessments in coming weeks.

Americans probably increased spending on cold, cough and throat remedies to $3.6 billion last year as the pandemic spurred demand for influenza relief, Mintel International Group Ltd. said in October. The London-based research company estimated U.K. consumers spent 428 million pounds ($653 million) in 2009 alleviating flu symptoms with products that don’t require a doctor’s prescription.

$10 Billion in Sales

Pharmaceutical companies reaped at least $10 billion in sales of vaccines and antivirals because of the outbreak, according to data compiled by Bloomberg. Roche of Basel, Switzerland, sold about $3.58 billion of Tamiflu last year and in the first three months of 2010. London-based GlaxoSmithKline Plc’s revenue from the pandemic reached $3.78 billion.

Novartis AG of Basel, Paris-based Sanofi-Aventis SA, CSL Ltd. of Melbourne and Baxter International Inc. of Deerfield, Illinois, also sold vaccines.

WHO came under fire over its handling of the pandemic, and the BMJ, formerly known as British Medical Journal, published a report in June saying the agency was swayed by experts who received money from Roche and Glaxo. Chan denied the claim, saying her decision to declare a pandemic was based on defined criteria.

‘Raked Over the Coals’

“It is a lot easier to look at things with 20:20 hindsight than having to take decisions in real time with limited or partial information,” WHO’s Hartl said. “We would have been raked over the coals had we not taken any precautions and it turned out to be a much more severe virus.”

Seasonal flu kills as many as 500,000 people a year, according to WHO statistics. The full death toll from swine flu won’t be known until a year or two after the pandemic, the agency said.

Unlike seasonal flu, which kills predominantly the frail elderly, at least a fifth of those who died from swine flu were healthy adults with no underlying conditions, according to Sylvie Briand, head of WHO’s global influenza program.

Children younger than two years, pregnant women, people with lung diseases, metabolic disorders, weakened immune systems and certain neurological conditions are among groups at higher risk of developing a severe disease, WHO said in November. H1N1 also poses greater risk of complications in obese individuals and disadvantaged and indigenous populations, it said.

Seasonal Flu Behavior

The pandemic virus is now behaving more like seasonal influenza in New Zealand, where it’s causing sporadic cases and clusters of infections in communities that may have avoided the disease last year, said Lance Jennings, a clinical virologist with Canterbury Health Laboratories in Christchurch. At least one in four New Zealanders had some immunity to H1N1 as early as March, the country’s health ministry said on June 4.

“The threat of an outbreak similar to the size of last year’s in the Southern Hemisphere is certainly diminishing,” said Jennings, who has studied flu for more than 30 years.

Australia’s flu season doesn’t seem to have started yet and no significant changes have been noted in the pandemic flu viruses collected so far, said Anne Kelso, director of the WHO Collaborating Centre for Reference & Research on Influenza in Melbourne. Two out of five viruses tested at the center so far have been seasonal strains known as type B and H3N2, she said.

Lessons Learned

Swine flu is even less common in South Africa, where six cases have been identified, compared with 90 infections from type B and 69 from H3N2 this winter, said Barry Schoub, executive director of the National Institute for Communicable Diseases, in Johannesburg. That’s in contrast to the 2009 winter, when the new H1N1 virus supplanted seasonal strains, a typical feature of a pandemic.

“We would fully support the post-pandemic phase announcement,” Schoub said in an e-mail yesterday. The decision would shift the focus to addressing the long-term health and social impact of the pandemic, as well as to restoring normal functions, according to WHO guidelines. The agency would also review lessons learned and tweak recommendations on surveillance.

The pandemic highlighted the unpredictable nature of influenza and showed that planning for responses to global outbreaks requires greater flexibility, Canterbury Health’s Jennings said.

Closing schools and screening travelers at entry ports didn’t stop the virus, and the pandemic response wasn’t justified by its severity, said Heath Kelly, head of epidemiology at Victoria state’s infectious diseases reference laboratory in Melbourne. Apart from increased admissions to intensive-care wards, the pandemic may have been no more severe than a bad winter flu season, with reported cases inflated by increased testing and doctor visits, Kelly said yesterday.

To contact the reporter on this story: Jason Gale in Singapore at j.gale@bloomberg.net.

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