By Stephen Young
By Stephen Young
By Stephen Young
By Jim Schutze
By Rachel Watts
By Lauren Drewes Daniels
While young children are three times more likely to contract chronic hepatitis B than are older kids and adults, transmission of the virus from one child to another is uncommon: Fewer than five new cases of chronic hepatitis B occur among children annually in Texas.
The first hepatitis B vaccine appeared on the market in 1982, when Merck & Co. licensed Hepavax. Like most vaccines being produced at the time, Hepavax was manufactured using purified plasma from infected blood. Four years later, after fears arose that certain shipments of Hepavax may have been contaminated with the HIV virus, the company received FDA approval for Recombivax, the first genetically engineered vaccine. In 1988 SmithKline Beecham licensed its hepatitis B vaccine, Engerix, which, like Merck's product, is manufactured from a reproduced DNA strand of the virus.
But while the risk of hepatitis B appears minimal, the vaccine has been blamed for some 25,000 adverse reactions nationwide between July 1990 and October 1998, according to the federal Vaccine Adverse Events Reporting System, or VAERS, which collects anecdotal evidence from pediatricians, family physicians, and other health-care providers.
In 1996 Breonna was diagnosed as having chronic fatigue syndrome, an autoimmune disorder. Her doctor filed a VAERS report attributing Breonna's illness to a hepatitis B vaccine reaction. It was one of roughly 1,100 adverse reactions reported in Texas between July 1990 and October 1998, including 33 deaths, 370 emergency-room visits, and 93 hospitalizations. About 20 more vaccine recipients became "disabled," though the length and severity of the disabilities are difficult to discern from the available data.
The consensus from the CDC down to local health departments, however, is that serious adverse reactions are extremely rare. A recent CDC report concluded that fewer than 10 people per million will become ill from the vaccine, while 1,200 people out of every one million are at risk of death from hepatitis B-related illness.
Moreover, public-health officials who make and carry out vaccine policy in the United States say the mandatory vaccination of children is the only way to combat the spread of the virus among the higher-risk adult population.
"The notion of policy on this vaccine is, as it is with all vaccines, a trade-off between risk of the vaccine versus risk of the disease," says R. Palmer Beasley, dean of the University of Texas at Houston School of Public Health. "The trick is determining whether there is any causation [between the vaccine and the reaction]. The general belief has been--and I still believe this--that there are essentially no risks to the hepatitis B vaccine other than you get a needle and you get a little inflammatory action and it hurts for a few days."
But, citing the thousands of VAERS reports, parents groups and vaccine-safety advocates are raising questions about the safety of Recombivax and Engerix. The debate has intensified in recent months, starting in September, when the television newsmagazine 20/20 reported on the death and serious injury of a handful of American children who received the three-shot regimen. One month after the broadcast, France announced it was stopping its adolescent hepatitis B immunization program after studying the data on 800,000 immunizations.
Congress joined the discussion on May 18, when a House subcommittee held a public hearing in Washington, D.C., to begin to gather evidence and testimony on the vaccine's safety. Dozens of people, including the parents of children who had died or suffered serious illness after receiving the vaccine, urged the committee to ask Congress to fund studies that would determine the safety of Recombivax and Engerix, particularly in newborns.
That's not necessary, says Isabel Claxton of the vaccine-research division of Merck & Co. Claxton says it's hard to know what to say to people who believe their children were killed or injured by the vaccine.
"They want to find blame. They want an explanation for this, where there is no explanation. So they decided it was the vaccine," Claxton says. "I can't even begin to understand their grief, because I haven't been there myself. What I do believe--very strongly--is that you cannot say it was the vaccine; you cannot prove it was the vaccine. But think about the number of grieving parents we're saving through vaccination."
Clearly this is the view held by public-health officials like Palmer Beasley, who points out that roughly one billion people have received the hepatitis B vaccine worldwide. Any large number of "adverse circumstances" have probably occurred by chance alone, he says.
"Coincidence doesn't establish causation," says Beasley, who was an advisor to the World Health Organization's campaign to implement universal hepatitis B vaccinations in Taiwan. "I have personally administered thousands of hepatitis B immunizations, and I have never seen the kinds of severe reactions that are being reported. That's not evidence, that's just my experience."
So where is the evidence? Does it even exist?
Every few years, a committee of the Institute of Medicine, a research and advisory arm of the National Academy of Sciences, collects and reviews data on adverse vaccine reactions, as well as their possible causes. The committee's most recent report was issued in 1994, though it's difficult to determine what the committee members really thought about the potential dangers of receiving a hepatitis B vaccination.
On the one hand, the committee cited "biological plausibility" for a host of serious illnesses resulting from hepatitis B vaccine, including Guillain-Barre syndrome, multiple sclerosis, and rheumatoid arthritis. It even warned that the vaccines appeared to cause an allergic reaction called anaphylaxis that can be fatal. On the other hand, the committee said it didn't have enough evidence to make a definite connection between the vaccines and the adverse reactions.