Studies question effectiveness of flu treatments.

The studies published today reinforce the shortcomings of our efforts to control influenza.

 

 

As governments around the world stockpile millions of doses of flu vaccines and antiviral medicines in anticipation of a potential influenza pandemic,two new surprising research papers published Thursday have found that many of the standard treatments now in use are far less effective than previously thought.

 

"The studies published today reinforce the shortcomings of our efforts to control influenza " wrote Dr Guan Yi,a professor at the University of Hong Kong,in an editorial that accompanied the papers.The two studies were published early online by the British medical journal the Lancet because of their important implications for the coming flu season.

 

In one paper,international researchers analysed all the data from patient studies on the flu vaccine performed worldwide in the past 37 years,and discovered that the vaccine showed at best " a modest " ability to prevent infection with influenza or its complications in elderly people.The same vaccine is used globally.

 

"The runaway 100 percent effectiveness that's touted by proponents was nowhere to be seen "
said Tom Jefferson,leasd scientist for the historical vaccine study.Jefferson is a Rome-based researcher with the Cochraine Vaccine Fields project,an international consortium of scientists who systematically review research data.

 

"THere is a wild overestimation of the impact of these vaccines in the community " he said." In the case of a pandemic,we are unsure from the data whether these vaccines would work on the elderly."

 

In the second paper,researchers from the US Centers for Disease Control and Prevention said they had found that influenza viruses,particularly those from the bird flu strain,had developed high rates of resistance to the only class of cheap anti-viral medicines-drugs that have been used for 30 years,mainly to treat flu once patients have caught the virus.

 

"We were alarmed to find such a dramatic increase " said Dr Rick Bright of the Centers for Disease Control in Atlanta.He added, " Our report has broad implications for agencies and governments planning to stockpile these drugs for epidemic and pandemic strain of influenza."

 

Before  2000 almost no virus was resistant to the drug Amantadine.By 2004,15 percent of influenza-A viruses collected in S Korea,70 percent in Hong Kong and 74 percent in China were impervious.During the first six months of 2005,15 percent of the influenza-A viruses in the US were resistant,up from 2 percent just one year before.

 

All human cases of the bird flu A (H5N1) strain,which is still extremely rare in humans,have been resistant,the researchers said.

 

The immediate implications of these findings are most ominous for the developing world,because wealthier locations-European countries and places like the US,Hong Kong,S Korea and Singapore-have been stockpiling newer,vastly more expensive antiviral medicines like Tamiflu,which are still on patent but are effective against the disease.

 

Even for wealthier countries,the research is alarming because it demonstrate how quickly and unexpectedly flu viruses can become impervious to medicines once the medicines are put into common use.

 

Also,antiviral medicines do not cure influenza.They cut down on transmission of the disease and reduce some what the symptoms and complications,including the rate of associated pneumonia,in those already infected.

 

Called for comment,Dick Thompson,a spokesman for the World Health Organization,said that the agency could neither support nor deny that the findings of the historical vaccine analysis,though he said some experts had criticized the researchers for " not including some important past studies " in their sample.

 

But the viruses increasing resistance " is a finding that is being discussed widely within the flu world and will bear careful monitoring " he said,noting that he was not aware  of any country in the developing world that had been able to stockpile the more expensive drugs.

 

THe current bird flu virus does not spread easily-if at all - from human to human,and so has little potential to become a worldwide human scourge.But the WHO has warned that it could acquire that potential through a couple of common biological processes and that countries should prepare for a wave of serious influenza.

 

The finding that flu vaccines have only a modest effect for the elderly is particularly worrisome,because that group tends to suffer high rates of complications and deaths from the disease,and vaccination is standard practice.In people older than 65,the historical study said,the vaccines "a re apparently ineffective  " in the prevention of influenza,pneunomia and hospital admission,although they have reduced deaths from pneunomia by " up to 30 percent "

 

" What you see is that marketing rules the response to influenza,and scientific evidence comes fourth or fifth " Jefferson said " Vaccines may have a role,but they appear to hava a modest effect.The best strategy to prevent the illness is to wash your hands."

 

The research showed,however,that vaccine offered better protection is nursing home patients,who suffered significantly lower rates ofcomplication like pneunomia if inoculated.

 

In terms of antiviral drugs,.30 countries have placed huge orders for Tamiflu,the most popular of the newer,more expensive antiviral medicines,said Martina Rupp,a spokeswoman for Roche,a pharmaceutical company based i n Basel,Switzerland.The company is offering a " substantial discount " for public health purchases.

 

Researchers speculate that one reason why resistance rates to the older,cheaper antiviral drugs in Asia jumped so much starting in 2000 and skyrocketed after 2002,is that doctors there started prescribing the drugs far more widely after the advent of bird flu in 1997 and sudden acute respiratory syndrome ,or SARS ,in 2002.

 

 

Tests find avian flu can't spread easily.

 

A woman's death of avian influenza in Jakarta has caused considerable alarm there,but genetic tests performed in Hong Kong on samples of th e virus from the woman showed Wednesday that the virus had not yet mutated in ways likely to make it more of a threat to people.

 

The genetic evidence suggests that cases identified so far in Indonesia may be no more dangerous by themselves than the nearly 100 cases recorded since the beginning of last year in Thailand and Vietnam.But the disease remains a potentially serious threat to human health because it could still evolve to become more readily transmissible among people.

 

The virus in the dead woman " seems like a virus that has gone directly from birds " sadi Dr George Petersen,the WHO's representative in Jakarta.He called that " reassuring fo r all of us "

 

The government of Indonesia had declared Monday that the disease was an "extraordinary event " a step allowing additional spending beyond usual budget  restraints,and allowing the governments to force suspected victims to be hospitalized and isolated.A half dozen people with flulike symptoms have been isolated,and Siti Fadila Supari,the Indonesian health minister,warned Wednesday that the disease was becoming an epidemic.He later withdrew the remark.

 

The Indonesian government has also begun an extensive slaughter of chickens in or near flocks where birds have been infected with the disease.Petersen said that a genetic sequence analysisi of the virus from the dead woman,a 37-year old worker at Jakarta's airport,had just been completed in Hong Kong.

 

Health officials around the world have been watching to see if the virus will evolve to acquire the capability to pass easily from person to person,a necessary step for the virus to start a pandemic.

Malik Peiris,the Hong Kong University expert who did the genetic sequence,cautioned that not all of the virus had been analyzed yet but that the segments analyzed so far matched avian versions of the virus.

 

This suggests that the virus has not mixed with human flu viruses,thereby acquiring genetic material that would allow it to pass more easily among people.

 

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