Excessive reliance on Tamiflu in the fight against avian influenza may have unpredictable consequences, warn Italian scientists.
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Tamiflu (Image: News.Yahoo) |
In the British journal Lancet, experts assert that there is no evidence to suggest that the current top flu medication is fully effective against the H5N1 virus and may be less utilized once the virus mutates into a pandemic strain.
Tamiflu and Relenza primarily serve to alleviate flu symptoms and shorten the duration of illness. They are not a cure. However, it is still believed that these two drugs play a crucial role in mitigating a pandemic when the H5N1 virus mutates into a strain that can easily spread from person to person. By administering them immediately at the site of a new virus outbreak, it is thought that the spread of the virus can be prevented or at least slowed. With this belief, governments around the world are racing to stockpile them, especially Tamiflu.
However, the Cochrane Vaccines organization (Italy) warns against placing excessive trust in this preventive measure. The medication is only effective when applied alongside simple preventive measures such as isolating patients, encouraging the community to wear masks, and promoting regular handwashing.
The authors, led by Dr. Tom Jefferson, conducted a meta-analysis of several previous studies on Tamiflu and Relenza, along with two older products, amantadine and rimantidine, with the goal of evaluating their efficacy and safety.
The results showed that Tamiflu and Relenza do indeed reduce symptoms and shorten the duration of illness when administered within 48 hours after infection. They also help prevent pneumonia and throat inflammation — complications of the flu.
However, no medication was effective in individuals without symptoms, even if they carried the virus. Additionally, Tamiflu does not completely alleviate nasal symptoms. Meanwhile, the World Health Organization (WHO) has confirmed that when experiencing a runny nose and sneezing, H5N1 patients excrete a viral load ten times higher than that of typical flu patients, thus increasing the risk of transmission.
Jefferson’s team also investigated the effects of Tamiflu on three avian influenza strains: H5N1, H7N7, and H7N3. The results indicate that Tamiflu does not reduce the mortality rate of the H5N1 virus. Another potential risk is the relatively high resistance to Tamiflu (16%) observed in cases from Japan and Vietnam.
Meanwhile, the Middle East has become a new focal point for disease outbreaks. Iran and WHO are investigating whether avian influenza has killed a 15-year-old girl. Iran serves as a stopover for migratory birds from Turkey. Experts warn that controlling an outbreak here will be very challenging due to the country’s lack of resources. In neighboring Turkey, at least 21 people have been infected with H5N1. China has also reported its sixth death from avian influenza.
Mỹ Linh (according to AFP)