Experts say H1N1 vaccine is safe and time-tested
By William Mullen
Rushed into production? Not really.
Full of substances that do harm? Hardly, and especially not compared with 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 online.
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 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 monthslong 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 worried that the vaccine was rushed into production before being tested adequately for potential side effects.
Nonsense, Alexander 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," he said.
Pharmaceutical researchers around the globe are trying to find newer and speedier ways to make flu vaccines, but 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.
The alternative, nasal-spray vaccine is made using a live virus. It too is grown in eggs, but at lower temperatures, weakening or "attenuating" it so it can survive only in the nose, not at greater body temperatures 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 firms 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 harmless, trace amounts. "If we looked at acetylsalicylic 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. Also, researchers 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."