Published on April 21, 2005 - Many people who are now familiar with growing warnings about a new influenza pandemic are expressing little concern. They simply quote headlines supporting their belief that vaccines and antiviral drugs will protect them.

Even Public Health Minister Dr Suchai Charoenratanakul told The Nation: “Don’t worry. Today’s medical technology can handle this.”
But most medical experts believe this is an exaggeration, and greatly fear the repercussions of failing to measure up to public expectations when a pandemic arrives.

“It could take six months [after the pandemic starts] for a vaccine to be ready and a year before we can get some of it,” predicts

Dr Tawee Chotpitayasunondh, chief of Thailand’s pandemic medical response team. Vaccines created from the 1997 and 2003 H5N1 flu strains that infected people in Hong Kong have both proven ineffective against the H5N1 virus that surfaced in Thailand last year. This highlights the fact that, where vaccines are concerned, it’s impossible to make the cure until the disease itself is known.

Our biggest hope for protection comes from human trials of an H5N1 vaccine now underway in the US. This vaccine is based on the 2004 strain.

However, World Health Organisation officer in Thailand, Dr Somchai Peerapakorn, warns that the new vaccine may not work at all and, even if it does, there will be difficulties in getting supplies of it. Currently, Thailand can’t even get its hands on enough seasonal flu vaccine for its health workers. Tawee says the Public Health Ministry placed an order for 150,000 doses this year, but so far has received only one third of that amount.

Worldwide production of influenza vaccine amounts to only 300 million doses a year. It is produced in just a handful of countries.

“That’s why I believe Thailand should take part in human trials of the [new US ] vaccine, so that we can get some,” says Siriraj Hospital’s Dr Prasert Thongcharoen.

Tawee goes further. He wants Thailand to move forward on it’s own vaccine factory. “They are complicated, but Vietnam’s on the path toward developing the capacity, so there’s no reason why Thailand can’t do the same.”

Thailand faces similar challenges with the only other pharmaceutical defence against virus infection, the antiviral drug known as Tamiflu. Of three types of antiviral drugs, Tamiflu is the only one that has proven effective against the H5N1 virus. It inhibits a protein on the surface of the virus, making it incapable of infecting new cells. But treatment needs to begin within 48 hours of the onset of symptoms.

Its manufacturer, the Swiss pharmaceutical firm Roche, has the capacity to produce only about 1.5 million doses a year. Japan currently receives 80 per cent of that production and, with growing concern over H5N1, other countries are queuing up for what’s left.

Although Roche plans to increase its production to four million doses, most of it will go to North America, Europe and Australia. Thailand is aiming to stockpile 325,000 doses over the next five years. It has received 30,000 doses so far. This is not a lot when the government estimates as many as 26 million Thais could become ill in the coming pandemic.

There’s another problem: Tamiflu is not cheap. It costs about Bt125 per capsule, or Bt1,250 for a 10-capsule dose. Tawee and others are exploring the possibility of purchasing the drug in a bulk powder form suitable for stockpiling. They believe this could slash costs to one-third of the normal level.

“When the pandemic arrives, we can just dissolve it in water for people to take orally,” he says.

But that may not be the end of the problem. Another emerging variable is the possibility that Tamiflu, like other antiviral drugs, may be ineffective against the form of the virus that causes the pandemic. Vietnamese doctors have reported that some of their H5N1 patients have died regardless of when they started receiving Tamiflu. When asked about these uncertainties, Suchai agrees that there is no vaccine available, but insists that Thailand has sufficient stockpiles of Tamiflu. Ultimately though, he admits to a rather bleak acceptance of how relatively powerless we are.

“This world belongs to viruses and bacteria,” he says.

Nantiya Tangwisutijit
The Nation