Swine flu now unstoppable, says WHO

Philippine Daily Inquirer
First Posted 04:34:00 07/15/2009

MANILA, Philippines—The swine flu pandemic has grown “unstoppable” and all countries will need access to vaccines, a World Health Organization official said on Monday, as seven new deaths were reported and a study raised fresh concerns.

Britain, Thailand and the Philippines all reported deaths on Monday, while Saudi Arabia shut an international school after 20 students were diagnosed with the Influenza A(H1N1) virus.

As the death toll increased, the WHO official said a swine flu vaccine should be available as early as September and all countries would need to be able to protect themselves.

A group of vaccination experts concluded after a recent meeting that “the H1N1 pandemic is unstoppable and therefore all countries would need to have access to vaccines,” said Marie-Paul Kieny, WHO director on vaccine research.

Health workers should be at the top of the list for vaccination since they will be in high demand as people continue to fall sick, she added.

Countries would be free to decide on their national priorities, but other groups should include pregnant women and anyone over six months old who has chronic health problems, the WHO official said.

Children as amplifiers

Particular attention would have to be paid to children since they are considered “amplifiers” of the spread of the virus, especially when gathered in schools, Kieny added.

Six public high schools, six public elementary schools and six private schools in the Philippines remain closed until July 20 for having confirmed cases of the flu, the Department of Education (DepEd) said Tuesday.

Some 187 students at San Pablo National High School in San Pablo, Laguna, are under observation after five students tested positive for the swine flu virus, the DepEd said.

More than 90,000 swine flu cases have been reported worldwide, including 429 deaths, the most recent WHO numbers from last week show.

Most of the deaths reported on Monday were in Asia, with Thailand reporting three fatalities and the Philippines two. Thailand’s death toll has now reached 21, while the Philippines has three deaths.

Elderly’s extra immunity

Several reports showed the new virus attacks people differently than seasonal flu—affecting younger people, the severely obese and seemingly healthy adults, and causing disease deep in the lungs.

The elderly seem to have some extra immunity to this new H1N1, which is a mixture of two swine viruses, one of which also contains genetic material from birds and humans. It is a very distant cousin of the H1N1 virus that caused the 1918 pandemic that killed 50 million to 100 million people.

A study published in the journal Nature on Monday confirmed that the blood of people born before 1920 carries antibodies to the 1918 strain, suggesting their immune systems remember a childhood infection.

Obesity risk factor

The work by Dr. Yoshihiro Kawaoka also supports other studies that this new H1N1 strain does not stay in the nose and throat, as do most seasonal viruses.

“The H1N1 virus replicates significantly better in the lungs,” Kawaoka said. Other studies have also shown it can cause gastrointestinal effects, and that it targets people not usually thought of as being at high risk.

“Obesity has been observed to be one of the risk factors for more severe reaction to H1N1”—something never before seen, Kieny added. It is not clear if obese people may have undiagnosed health problems that make them susceptible, or if obesity in and of itself is a risk.

211 deaths in the US

On Friday, a team at the US Centers for Disease Control and Prevention (CDC) and the University of Michigan reported that nine out of 10 patients treated in an intensive care unit there were obese.

They also had unusual symptoms such as blood clots in the lungs and multiple organ failure. None have recovered and three died.

The CDC estimates at least a million people are infected in the United States alone and clinics everywhere are advised not to test each and every patient, so keeping an accurate count of cases will be impossible. The United States has documented 211 deaths.

More damage to lungs

While most cases have been considered mild, a study released on Monday said the virus causes more lung damage than ordinary seasonal flu strains but still responds to antiviral drugs.

Virologists tested samples of the virus taken from patients in the United States as well as several seasonal flu viruses on mice, ferrets, macaque monkeys and specially bred miniature pigs.

They found that A(H1N1) caused more severe lung lesions among mice, ferrets and macaques than the seasonal flu viruses.

But it did not cause any symptoms among the mini-pigs, which could explain why there has been no evidence that pigs in Mexico fell sick with the disease before the outbreak began among humans.

First line of defense

The team also found that the virus was highly sensitive to two approved and two experimental antiviral drugs, including Tamiflu, now being hurriedly stockpiled around the world.

This confirms the drugs’ role as a “first line of defense” against the flu pandemic, the team said.

The worry about the present strain of A(H1N1) is that it could pick up genes from other flu strains that would enable it to be both highly virulent and contagious, said the new study.

Another concern is that the virus could acquire mutations enabling it to be resistant to Tamiflu.

Australians to be immunized

In Australia, authorities scrambled Tuesday to immunize its entire population against swine flu if necessary.

Australia, where the swine flu strain has infected almost 10,000 people and been linked to 19 deaths, said it was placing an advance order for 21 million courses of a vaccine that is now under development.

South Korea has reported no deaths but is also ordering vaccines, in its case enough for 13 million people—more than a quarter of the population.

2M high-risk people

Densely populated Hong Kong, which was paralyzed by an outbreak of Severe Acute Respiratory Syndrome in 2003, said this week it was buying enough swine flu vaccine to cover two million high-risk people.

Sanofi-Aventis, Novartis, Baxter, Schering-Plough’s Nobilon, GlaxoSmithKline, Solvay, CSL and AstraZeneca’s MedImmune are among those working on flu vaccines. Reports from Reuters, AFP and Edson C. Tandoc Jr.

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Everyone should be very careful and take all precautionary measures to prevent the spread of the pandemic flu virus.