Swine flu vaccines are safe and time-tested, experts say

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(Brian Cassella/Chicago Tribune/MCT)
Patrick Wilson, a research immunologist at the University of Chicago, is photographed in his lab, October 13, 2009. Wilson says the nasally administered vaccine can lead to permanent immunity to the targeted flu virus.

CHICAGO — Untested? No.

Rushed into production? Not really.

Full of substances that do harm? Hardly, and especially not
compared to the dangers of the H1N1 flu virus.

That is the retort of researchers, scientists, federal
health authorities and others familiar with how swine flu vaccine is being
made, as they listen — at times with disbelief — to the debate about it
unfolding around kitchen tables and over the Internet.

They hear the arguments — about what’s in the vaccine,
whether it was made too fast, whether there are side effects — all the while
frustrated that decades of experience in making effective flu vaccines hasn’t
resulted in more public confidence that they got this one right, too.

“We’ve been baking this bread for 60 years, and we’re
pretty good at it, buddy,” said Kenneth Alexander, an infectious disease
expert at the University of Chicago.

For all who will listen, Alexander and other experts at
research facilities, the U.S. Department of Health and Human Services, the U.S.
Centers for Disease Control and Prevention, the U.S. Food and Drug
Administration and elsewhere explain that the swine flu vaccine isn’t a
completely new brew cooked up in a panic.

They argue that it’s actually the result of a 60-year-old, tried-and-true
process of flu vaccine making that was tested on thousands of people before
being scheduled for distribution — including on some researchers who
volunteered themselves.

“A lot of misinformation is being brought up and spread
around,” said Jesse Goodman, the FDA’s acting deputy commissioner for
public health. “We think it is important to have the actual facts laid out
and let people make their own decisions.”

The vaccine “is the absolute best protection and a
perfectly safe one,” Goodman said, adding that the risks from contracting
the flu, which can be deadly, far outweigh any risk of side effects from the
vaccine.

Here is how the vaccine is made: When the H1N1 virus first
appeared last April in Mexico and California, federal health officials identified
it and sent it to pharmaceutical companies it contracts so they each could
formulate their vaccine versions for field testing before mass production.

It is a months-long process, but mass production geared up
in August and the first 2 million doses were delivered to doctors and clinics
two weeks ago. On Friday, CDC officials acknowledged slower production than
they’d hoped but predicted “widespread availability” by the beginning
of November.

That turnaround from discovery to delivery was fast enough
that many Americans who told pollsters they don’t plan to vaccinate their
children said they worried that the vaccine was rushed into production before
being tested adequately for potential side effects.

Nonsense, Alexander said.

“This H1N1 vaccine is made just like all the flu
vaccines we have been making for 60 years, which have an extraordinary record
for safety,” he said. “The only difference between this one and the
seasonal flu shots is the virus it is made from, so we have no reason to
believe this one will be any less safe.”

Though pharmaceutical researchers around the globe are
trying to find newer and speedier ways to make flu vaccines, in the U.S. the
only FDA-approved method is the original, 1940s way: injecting the virus into
chicken eggs to be grown into larger quantities.

For the arm-shot vaccine, the virus eventually is harvested
from the eggs, killed and chopped into segments. When injected into the
recipient, it activates the body’s immune system to produce antibodies that
kill the actual flu virus if the recipient is exposed.

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The alternative, nasal-spray vaccine is made using a live
virus. It too is grown in eggs, but at lower and lower temperatures, weakening
or “attenuating” it so that it can survive only in the nose, not at
greater body heats in the lungs.

“The nasal vaccine infects the mucosal cells (in the
nose), which are closely monitored by our immune system,” said Patrick
Wilson, a University of Chicago immunologist. Once that system detects the
vaccine, Wilson said, it produces permanent immunity to the targeted flu virus.

The first testing of both vaccines was performed on 3,000
volunteer recipients in eight laboratories at Baylor University, Cincinnati
Children’s Hospital, Emory University, Seattle Group Health Cooperative, St. Louis
University, University of Iowa, University of Maryland and Vanderbilt
University.

It also is being tested on volunteers by the five companies
licensed to make up to 250 million doses of the vaccine by next spring for the
U.S. market — CSL Limited, Novartis Vaccines, Sanofi-Pasteur Inc.,
GlaxoSmithKline, and MedImmune.

“It is tested to see if it produces the level of
antibody production in the blood that reaches the FDA standard,” said
William Schaffner, an infectious disease specialist at Vanderbilt. “It is
also tested for safety in the volunteers, something I know a little bit about
since I was one of the volunteers for this vaccine.”

On its Web site last week, the FDA posted the contents of
the vaccines produced by the five companies, including copies of the long,
multipage ingredient lists included with the doses at clinics. Schaffner said
that, like many everyday foods and medicines, they contain a number of vital
chemical substances that could be toxic in large volume but are included in
such tiny amounts that they are harmless.

“If we looked at acetyl salacylic acid, (the active
ingredient) in aspirin, taken in the current dosage it is an effective product
that can relieve headaches and reduce fevers. Taken by the handful, it can have
serious adverse events,” Schaffner said.

“So it is with vaccines. They have trace ingredients
that are in the vaccine for a variety of reasons. Taken together, the vaccines
have been proven safe not only in explicit clinical trials, but in demonstrated
use in hundreds of millions of doses over the years.”

The ingredient that anti-vaccine activists most question is
thimerosal, a preservative added in trace amounts to keep vaccine in two-shot
doses from deteriorating if stored while awaiting application.

Thimerosal contains ethyl mercury, and critics allege it can
cause autism and other neurological disorders. But researchers say there is so
little thimerosal in the vaccine that it poses no harm. Nevertheless, they have
produced thimerosal-free single-shot doses that can be ordered, and say there
is no thimerosal in the nasal spray.

“I continue to be amazed that people bring this issue
up,” said Paul Offit, a pediatrician and noted University of Pennsylvania
vaccine researcher. “There have been six exhaustive studies (of a possible
link between thimerosal and autism). … They each came back with a definitive
answer: no. Three other studies were done to see if thimerosal caused any signs
of mercury poisoning. All three answered: No.”

Others have raised concerns about “adjuvants” —
compounds sometimes added to vaccines to stimulate the immune response in
recipients. It is added in several European nations, but not in the U.S. Anne
Schuchat, the CDC’s director of immunization and respiratory diseases, said the
U.S. sees no need to add them unless the virus mutates into a far deadlier
form.

“Since April this flu has caused tens of thousands of
hospitalizations and more than a thousand deaths,” Offit said. “This
is only October and influenza is a winter disease, so no telling what we are
about to see.

“We should thank the Lord that we have this vaccine at
this stage.”