Article: 2 Studies Question the Effectiveness of Flu Vaccines

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The New York Times

 

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September 21, 2005

2 Studies Question the Effectiveness of Flu Vaccines

By ELISABETH ROSENTHAL

 

Rome, Sept. 21 - Just as governments around the world are stockpiling

millions of doses of flu vaccine and antiviral drugs in anticipation of

a

potential influenza pandemic, two new research papers published today

have found that such treatments 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 virologist 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 implications for the upcoming flu season.

 

In one paper, international researchers analyzed all the data from

patient

studies on the flu vaccine performed worldwide in the past 37 years and

discovered that vaccines showed at best a " modest " ability to prevent

influenza or its complications in elderly people.

 

" The runaway 100 percent effectiveness that's touted by proponents was

nowhere to be seen, " said Tom Jefferson, a Rome-based researcher with

the Cochrane Vaccine Fields project, an international consortium of

scientists who perform systematic reviews of research data.

 

" There is a wild overestimation of the impact of these vaccines in the

community, " Dr. Jefferson 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 Centers for Disease Control

found that influenza viruses, particularly those from the dreaded bird

flu

strain, had developed high rates of resistance to older and cheaper

antiviral drugs - rates that have escalated rapidly since 2003,

particularly in Asia.

 

" We were alarmed to find such a dramatic increase in drug resistance in

circulating human influenza viruses in recent years, " said Dr. Rick

Bright

of the Centers for Disease Control, in Atlanta. " Our report has broad

implications for agencies and governments planning to stockpile these

drugs for epidemic and pandemic strains of influenza. "

 

Before 2000, almost no virus was resistant to the drug Amantadine. By

2004, 15 percent of influenza A viruses collected in South 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 United States were resistant, up from 2 percent the year before.

All human cases of the bird flu (H5N1) strain - which is still

extremely rare in humans - have been resistant, the researchers said.

 

The immediate implications of these finding are most ominous for the

developing world, because wealthier nations have been stockpiling

newer and vastly more expensive antiviral medicines, like Tamiflu,

which are effective against the disease but still on patent.

 

Even so, the research is alarming because it demonstrates how quickly

and unexpectedly flu viruses can become impervious to medicines once

they are put into common use, as they would be in the case of a

pandemic. Also, at their best, antiviral medicines do not cure

influenza. They cut down on transmission of the disease and reduce

somewhat the symptoms and complications in those already infected,

including the high rate of associated pneumonias.

 

Called for comment, a spokesman for the World Health Organization,

Dick Thompson, said that the group could neither support nor deny the

findings of the analysis of vaccine studies at this point, noting only

that some experts criticized the researchers for " not including some

important past studies " in their sample.

 

But the problem of resistance " is a finding that is being discussed

widely

within the flu world and will bear careful monitoring, " Mr. Thompson

said, noting that he was not aware of any country in the developing

world that had been able to stockpile the newer drugs.

 

Anticipating a possible flu pandemic caused by a variant of the bird flu

virus - which belongs to the influenza A group - countries have been

aggressively buying up antiviral medicines and contracting to purchase a

flu vaccine against that strain, even though it is still under

development.

 

The United States has ordered $100 million worth of vaccine and Italy

$43 million worth, for example.

 

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 World Health Organization has warned that it could

acquire that potential through a couple of common biological

processes, and that countries should prepare for a possible wave of

serious influenza.

 

The fact that the current study showed that flu vaccines have had only a

modest effect in the elderly is particularly worrisome, since this a

group

that tends to suffer high rates of complications and deaths from the

disease and vaccination is currently standard practice. In people over

65, the vaccines " are apparently ineffective " in the prevention of

influenza, pneumonia and hospital admissions, although they did reduce

deaths from pneumonia by " up to 30 per cent. "

 

" What you see is that marketing rules the response to influenza, and

scientific evidence comes fourth or fifth, " Dr. Jefferson said.

" Vaccines

may have a role, but they appear to have a modest effect. The best

strategy to prevent the illness is to wash your hands. "

 

The research showed, however, that vaccines offered better protection

in nursing home patients, who suffered significantly lower rates of

complications like pneumonia if inoculated.

 

In terms of antiviral drugs, 30 countries have placed huge orders for

Tamiflu, the most popular, newer, more expensive antiviral medicine, a

spokesman for Roche Martina Rupp, said. The company is offering it at

a " substantial discount " for public health purchases. The Dutch Health

Ministry has ordered 5 million doses, enough to treat one-third of the

population. The British Department of Health has ordered supplies to

treat 15 million.

 

Ms. Rupp would not give either the retail or the discounted price,

although pharmacists said a full course of the drug costs more than

$100.

 

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 of sudden

acute respiratory syndrome, or SARS, in 2002.

 

Although actual human cases of these two diseases have always been

rare, they are also quite deadly, so patients are sometimes started on

antiviral drugs when they develop a respiratory illness, even though

in most cases they will prove to have nothing more than a common cold.

 

This is because all antiviral medicines work only if they are started

within 48 hours of the onset of symptoms and, in that period, it is

generally impossible to tell if patients have a deadly strain of flu or

merely a mild virus.