H5N1: Need to add new drugs

Experts believe that having to depend too much on a specific drug when a pandemic occurs is a big mistake.

Relenza

Recently, it has been identified that the H5N1 avian influenza virus, which killed 60 people in Southeast Asia, has caused more than 1,000 deaths in Turkey.

British experts also analyzed samples taken from the bodies of wild birds sent from Romania and concluded that H5N1 was also the culprit for killing these birds. In both countries, thousands of birds were culled to prevent further spread of the virus.

Speaking to a committee investigating the risk of a bird flu outbreak in the British Senate, Jan Slingenberg, an official of the Food and Agriculture Organization of the United Nations (FAO), said ' bird flu virus H5N1 has now invaded Europe . '

Immediately, countries have increased stockpiling of Tamiflu, the main avian influenza antiviral drug introduced by the World Health Organization. Turkey has requested Swiss pharmaceutical firm Roche Holding AG to immediately supply 500 thousand boxes of medicines. Romania also said it is deploying tens of thousands of doses of this medicine. These reserve drugs will be used in the case of genetically engineered H5N1 virus and can spread from person to person.

Tamiflu is currently a very effective anti-virus treatment against H5N1 in humans, but a new study published in Nature shows that the situation may change. Analysis of H5N1 virus from a Vietnamese patient treated with Tamiflu showed that some viruses were somewhat resistant to this drug. This patient recovered after receiving high doses of Tamiflu, and it was not surprising that the virus appeared to be partially resistant. But the study also points out that this resistance may become a serious problem that scientists need to consider more carefully.

Mr. Yoshihiro Kawaoka, a virologist at Tokyo University (Japan) and head of the research team, said: ' We do not know how often this type of gene mutation occurs. We are too dependent on Tamiflu; We need more drugs '.

More new drugs are needed to prevent H5N1 resistant virus. According to him, ideally countries should continue to store Tamiflu. But there should be many other drugs to fight bird flu, like a second line. In addition to Tamiflu, another known drug that kills the virus that appears to be resistant to the drug is Relenza. However, there are very few countries stocking this drug. Only Germany has stocked this drug in large quantities, in addition to a number of other European countries and the United States has a little reserve.

Albert Osterhaus, a virologist at Erasmus Medical Center in Rotterdam, Netherlands, agrees that drug companies have been slow to develop anti-virus drugs that can treat bird flu. . He also noted that although there are good substitutions for Tamiflu, Relenza also has limitations. He said: 'Tamiflu can be stored in large quantities and for a long time, but Relenza is difficult to store.' This drug is used with a spray bottle, making it unsuitable for young children as well as for severe patients. But Kawaoka and Osterhaus also agreed that more drugs should be developed.

And James Robertson, a virologist at the British National Institute of Biological and Control Standards, agrees that Tamiflu-resistant H5N1 is likely to become a major problem. ' This will happen. Once you start using Tamiflu in large quantities, resistance will appear . '

But he added that new studies have found that the partially resistant virus in this case is not as dangerous as the regular H5N1 virus. He said: ' Drug-resistant viruses appear to be weaker viruses; they also don't reproduce '. But a drug-resistant virus can have a second mutation and then it will be able to be stronger. Improper use of drugs can also create drug-resistant viruses. Mr. Kawaoka said that Tamiflu can relieve symptoms of human bird flu in just two days, causing people to stop taking the medicine; And this will help develop drug-resistant viruses. He said: ' To reduce the resistance of the virus to the virus, it is necessary to complete a course of treatment lasting five days '.

Nature, People