http://www.medicalconsumers.org/pages/FluVaccineisRarelyEffective.html
T housands of elderly
Americans are lining up for hours to receive a
flu shot. And the media are filled with stories
about the inadequacy of the flu vaccine supply
now that one of the only two suppliers had to be
shut down due to contamination. Nearly half the
nation's expected supply of influenza vaccine
has been wiped out.
In recent years, the federal government has been
promoting the flu vaccine for everyone, not just
for the elderly and the sick; but now it has had
to do a complete about-face. Because the supply
is so limited, the public has been told that
influenza vaccines should be reserved for the
elderly, the chronically ill, health care
workers, babies 6-23 months old, pregnant women
and women who plan to become pregnant in the
next four months. The public trust was shaken
soon after this announcement with the news that
members of Congress and at least one football
team got flu shots.
Understandably, a certain amount of hysteria has
erupted because flu vaccines have not reached
many of the people in the government's high-risk
category. Now everyone seems to want
the flu vaccine. It's time to step back and look
at the big picture. Time to look at the question
of how effective vaccines have been in
preventing the flu. More importantly, how
effective have vaccines been in reducing the
deaths and severe complications sometimes
associated with influenza?
As is commonly known, the vaccine formulation
changes each year. The three different flu
strains are usually chosen in the spring, and
the choice is based on a combination of
guesswork, flu outbreaks in Asia , and the
recommendations of the World Health
Organization.
What is not commonly known is this:
Researchers divide influenza into two types, and
the yearly flu vaccine is more likely to be
effective against the type that afflicts fewer
than 15% of all who appear to have
influenza—this is the one caused by influenza A
or B. Researchers refer to all other forms of
influenza as influenza-like illness .
Both types produce exactly the same
symptoms—headache, fever, muscle aches, cough
and runny nose.
All Influenza Looks Alike
In a telephone interview, vaccine researcher Tom
Jefferson, MD, explained, “The flu is not caused
by a single ‘bug'—about one-third of all
influenza is caused by an unknown agent; about
one-third are caused by rhinoviruses, the same
viruses that cause the common cold; and the
remainder are a mixed bag of other agents
including influenza A and B viruses and members
of the coronavirus family.”
What makes things complicated, according to Dr.
Jefferson, is that they all appear to be the
same illness. Moreover, one cannot forecast how
much of the influenza viruses in the upcoming
flu season will be influenza A or B, he
explained, “yet the public is never told this.”
Dr. Jefferson co-authored the first review of
all clinical trials in which healthy people
under age 60 were randomly assigned to receive a
flu vaccination or a placebo vaccine. (More on
that later.) And he recently wrote an editorial
entitled, “How to deal with Influenza?” for the
British medical journal, BMJ. Vaccination
successes are largely confined to influenza A
and B, the type that accounts for only a small
percentage of all influenza cases, he wrote.
What's more, public health officials are not
good at predicting how much influenza A and B to
expect in the next flu season. Putting these
concerns together, Dr. Jefferson expressed
reservations about mass vaccination, given the
costs and variable benefits. “Before committing
scarce resources to deal with influenza we need
better proof that what we see is influenza and
not an influenza-like illness.”
How good was last year's vaccine?
The panic over flu shots this season is an even
more extreme version of what occurred in
November 2003 when influenza broke out earlier
than usual in some parts of the country. The
public was warned that the flu season was going
to be much worse than previous years. Reports of
flu-related deaths among previously healthy
young children sent thousands of people to stand
in line for the flu vaccine.
But we are far enough away from last year's
crisis to learn that the flu vaccine of the
2003-2004 season was a flop. It was the first
time the federal government ever looked at the
effectiveness of the flu vaccine in the midst of
the flu season. The U.S. Centers for Disease
Control (CDC) and Prevention funded this study
which followed health care workers in Colorado ,
where the 2003-04 flu season started with a
vengeance.
Lab tests were given to the vaccinated as well
as the unvaccinated health care workers. Results
showed that last year's vaccine “was not
effective or had very low effectiveness against
influenza-like illness.” Still, the CDC managed
to put a positive spin on these pitiful
findings, stating that its study did not prove
that last year's vaccine was totally
ineffective.
CDC pushed vaccine known to be
ineffective
Here is how the CDC explained the poor
performance of the 2003-04 vaccine. “Last year,
the U.S. public health officials and the
companies that make vaccines miscalculated and
failed to predict that a new strain called the
Fujian influenza A would be the most common
cause of infection and left it out of the mix.”
The CDC explanation is more than a bit
disingenuous to consumer advocate Barbara Loe
Fisher, president of the National Vaccine
Information Center in Virginia .
As the consumer voting member of the FDA's
advisory committee on vaccines, Fisher
participated in the discussions regarding the
Fujian strain and why it was not included in the
2003-04 flu shot. As early as March 18, 2003,
Fisher said the advisory committee knew that
Fujian strain was the most important virus for
the upcoming flu season. “Federal officials were
prevented from replacing the A/Panama strain
with the Fujian strain emerging out of Asia and
being detected in Europe and the U.S. last
spring,” according to Fisher, “because
scientists in labs around the world were unable
to isolate and grow the virus in a way that
would allow vaccine production.”
In a telephone interview, Fisher said that the
transcripts of these discussions at the FDA are
publicly available (see below). “I called for
the federal health officials to be honest with
the American public about the effectiveness of
the [2003-04] flu vaccine,” she continued. (In
mid-January 2004, just as the time to be
vaccinated had passed, the CDC issued a press
release admitting the ineffectiveness of the
current flu vaccine.) The National Vaccine
Information Center , which Fisher co-founded in
1982, is a national, non-profit advocacy
organization that often points to the lack of
scientific evidence to support public policy
regarding childhood immunizations.
Efficacy of Vaccines Past for People
Under 60
It is, of course, too early to see whether the
CDC 2004-05 flu predictions are more accurate,
but for the first time a systematic assessment
has been conducted of all flu vaccine trials
worldwide. The review was conducted by the
Cochrane Collaboration* and Dr. Jefferson was
one of the four authors. The Cochrane reviewers
wanted to answer the question of how effective
flu vaccines are for healthy people under the
age of 60 years. They also wanted to see whether
there were any adverse effects.
They found 25 clinical trials in which healthy
people between the ages of 14 and 60 years had
been randomly assigned to have a flu vaccine or
a placebo (inactive) vaccine. All the trials had
been published in medical journals between 1969
and 2002. Altogether they involved 59,566
participants. Here is the Cochrane Review
conclusion: Influenza vaccines are effective in
reducing influenza A and B, but they do not work
against the overwhelming majority of
influenza-like illnesses.
When the Cochrane reviewers pooled the results
of all 25 trials, they found that only 6% fewer
vaccinated people got the flu, compared to the
unvaccinated people. The vaccine formulations,
which differed each year, were based on the
recommendations of the World Health Organization
or single governments (the 25 trials took place
in eight different countries). No adverse
reactions to the vaccines were reported.
The Cochrane review, which was published this
year, produced these additional findings: The
influenza vaccine did not reduce the number of
working days lost, nor did it reduce flu-related
complications, deaths or hospitalizations. From
a public health standpoint, another
disappointing finding was the failure of the
vaccines to stop the spread of influenza.
Elderly People
Dr. Jefferson and his colleagues are currently
conducting a similar Cochrane Review of all
vaccine clinical trials involving the elderly
(another one about children is in the works).
Surprisingly few randomized trials have been
conducted for the elderly and chronically ill.
In less well-designed studies (20 in all), the
influenza vaccine reduced the risk of pneumonia,
hospitalization, and death in people over 65.
People with asthma
Another Cochrane Review focused solely on the
benefit of the influenza vaccine to people with
asthma. It addressed two important questions:
Does the vaccine itself trigger asthma attacks?
Does it protect against asthma attacks caused by
influenza? Combined results of trials involving
adults with asthma and children with asthma came
to the same conclusion: Asthma attacks did not
increase in the two weeks following a flu
vaccination.
As for the question of whether the flu vaccine
reduces the rate of asthma attacks following
influenza infection (as opposed to the
vaccination itself), few trials have looked at
this crucial issue. The Cochrane Review, which
was published in 2003, concluded, “…uncertainty
remains in terms of how much difference
vaccination makes to people with asthma.”
Children and Babies
A yearly flu shot for healthy babies and
children is a relatively new policy in the U.S.
As noted, last year's reports of flu-related
deaths among healthy children drove many
panicked people to line up for flu shots. But
the CDC web site (as of October 22, 2004)
acknowledges that there is no way of knowing
whether more children than usual died of the flu
last winter. “Because the number of influenza
deaths in children has not been tracked before,
it's not possible to compare the number of
deaths in children this year with previous
years.”
As far as the CDC knows, 152 children died of
influenza in the 2003-04 season. For this
article, the CDC officials were asked how many
of these children had been severely ill before
they got influenza. Answer: “The CDC will report
these statistics at the end of this year.” (The
agency would not permit direct access to its
scientists for this article, so the answers to
all questions came via a press officer.) Since
CDC had used these deaths to promote flu shots
and has since admitted the vaccine was largely
ineffective, it is important to know more about
the children who died.
One imperfect study supports policy on
babies
The basis of the CDC recommendation for babies
between 6 and 23 months rests on one rather
imperfect study conducted in Colorado during
last year's flu season. It was a retrospective
study of the nearly 30,000 children enrolled in
a Kaiser Permanente health plan. The 6-23
month-olds represented only about one-sixth of
all the children in the health plan. The study
was funded by the CDC and led by Debra P.
Ritzwoller, PhD, research scientist in the
Research Unit at Kaiser Permanente, Colorado.
In a telephone interview, Dr. Ritzwoller was
asked to explain the results, as they were not
described clearly on the CDC Web site. Compared
to unvaccinated children, the vaccinated
children had 49% fewer cases of influenza,
according to Dr. Ritzwoller. This finding, she
noted, applied only to the children who had
influenza A or B. Whereas, there was a smaller
benefit to those with the more common
influenza-like illness: 25% fewer cases
among the vaccinated kids. But the key question
is: 49% and 25% of what? Dr. Ritzwoller was not
able to provide the answer. Here's why the
question is important: If few children in this
study got the flu, then these reductions are
less than meets the eye. For example, if 10,000
kids belong to a health plan, and only four of
the unvaccinated kids and three of the
vaccinated kids got an influenza-like illness,
that's 25% fewer cases.
The children had their illness type determined
in laboratory tests that were administered in
the emergency room. Unlike the well-designed
clinical trials that formed the basis of the
Cochrane Reviews, the Colorado Kaiser Permanente
study had not randomly assigned the children to
receive a flu vaccine or a placebo vaccine. This
study appeared online last summer in the MMWR
(Morbidity & Mortality Weekly Report), but is
yet to be published in a peer-reviewed journal.
When asked whether the flu vaccine caused any
adverse reactions, Dr. Ritzwoller said there
were none, but acknowledged some gaps in her
study. “Hospital admissions were not tracked,
and the parents were not interviewed,” she
explained, attributing this to inadequate CDC
funding.
The CDC's rationale for its relatively new
policy regarding yearly flu shots for babies
6-23 months is also based on their purportedly
worse incidence of influenza complications. But
consumer advocate Barbara Loe Fisher has her
doubts. Giving the flu vaccine to babies under
age two who are likely to receive other,
standard childhood immunizations at the same
doctor visit is a “national experiment,” said
Fisher.
She faults the CDC for creating hysteria about
the dangers of the flu—last year and this
year—without warning parents and doctors about
the unknowns surrounding the safety of the flu
vaccine in combination with other childhood
vaccines. The one exception she identified was
Prevnar, the pneumonia vaccine which has been
studied in combination with the flu vaccine.
Fisher is concerned about public health
officials “cavalierly adding yet another vaccine
to the childhood regimen without proof of safety
or efficacy.” A new Japanese study, published in
Pediatrics International, supports her concerns.
Japanese babies, aged 6 to 24 months, had been
vaccinated against influenza A and then
age-matched to unvaccinated babies.
All the babies were followed for three flu
seasons. The study found that the vaccine was
ineffective in preventing influenza A. What's
more, the research team led by Tao Maeda
concluded that influenza vaccination of healthy
infants and young children is not justified
unless the benefits clearly outweigh the risks.
More studies are needed, say the Japanese
researchers, before vaccinating children under
the age of two becomes public policy.
In conclusion
Most people will not get the flu (only 5-20%
come down with it each season, according to the
CDC). Influenza does not pose a risk of serious
complications to most people who get it. The flu
vaccine (which changes formulations each year)
does not prevent the type of flu that the
overwhelming majority of Americans get each
fall/winter season. The flu vaccine will cut the
odds of getting influenza A and B by only 25%.
This type of influenza, however, represents less
than 15% of all cases, and public health
officials cannot forecast how much of the
influenza viruses expected in the upcoming flu
season will be influenza A and B.
Elderly people may benefit from a flu
vaccination in terms of reduced risk of
pneumonia, hospitalizations and death, but the
supporting studies are not very good. There is
no good evidence to show that the benefits
outweigh the risks of vaccinating babies and
young children against the flu. Healthy people
under age 60 years do not benefit from the flu
vaccine, in terms of reduced odds of getting the
flu, days lost from work, or stopping the spread
of influenza. No adverse reactions to the flu
vaccine have been identified, though long-term
consequences are unknown.
For more information:
- Visit the CDC Web site (www.cdc.gov/flu), or
call the hotline at 1(800) 232-2522. This is
the vaccine policy-setting government
agency, and clearly not an objective source of
information. For example, the Web site explains
that the current vaccine shortage is due to the
fact that the British supplier to the U.S.
stopped production at the order of the British
version of the FDA, but fails to give the reason
(contamination).
- For an entirely different viewpoint, go to the
National Vaccine Information Center 's Web site
at (www.nvic.org/diseases/influenza.htm), or
call 1(703)938-0342. You will get an
explanation, for example, about the difference
between temporary immunity as delivered by a flu
vaccine and natural or permanent immunity as
conferred by recovering from the flu. The NVIC
offers a free fact sheet and newsletter about
influenza. At the Web site, you can read the
transcripts of last year's FDA advisory
committee meetings mentioned by Barbara Loe
Fisher in this article.
- At www.bmj.com, go the 9/18/04 issue of the
BMJ to read Dr. Jefferson's editorial, “How to
deal with influenza?”
- If you believe that the flu vaccine shortage
is due to lawsuits against pharmaceutical
companies, go to the Web site of the Washington,
DC-based, advocacy organization, Public Citizen
(www.citizen.org/documents/ACF7D6.pdf).
*The Cochrane Collaboration is an
international organization that conducts
systematic reviews of all relevant studies to
determine whether or not medical treatments
work. The reviews are maintained in a
subscription-only “library” online or in a CD
ROM format.
Maryann Napoli November 2004