Panel: Smallpox vaccine not for everyone
June 20, 2002 Posted: 6:18 PM EDT (2218 GMT)
Rhonda Rowland
CNN
ATLANTA, Georgia (CNN) -- A government advisory panel decided
Thursday not to reinstate widespread smallpox vaccination, yet the
equivalent of the population of a small town will be eligible for
inoculation against the disease.
An estimated 10,000 to 15,000 people could receive the vaccine, agreed
the Centers for Disease Control's Advisory Committee for Immunization
Practices. Included in the group are those who would be on the front lines
in treating smallpox should there ever be an outbreak -- doctors, nurses and
possibly even hospital housekeeping staff.
The decision came after the panel heard Wednesday from scientists who
argued against reinstating mass vaccinations for the general public.
Routine smallpox vaccinations were discontinued in the United States in
1972, and the disease was eradicated globally in 1980. But after the
September 11 terrorist attacks, government officials began stockpiling
vaccine and looking at U.S. vaccination policy because of the possible use
of the virus in a biological weapon.
Dr. Walter Ornstein, director of the Centers for Disease Control and
Prevention's National Immunization Program, said diphtheria, measles and
mumps are much more contagious than smallpox, which is not easily
transmitted airborne -- and smallpox's obvious symptoms would key doctors
into its presence quickly. The smallpox vaccine is effective even if given
several days after a person is exposed to the disease.
Ornstein cited data from cases of smallpox in Europe between 1955 and
1971 that showed 55 percent of those who acquired the disease did so at a
hospital and another 20 percent were infected by a family member.
"Most transmission is predictable," he said. "About 93 percent can be
predicted."
How big a threat?
But Dr. Donald A. Henderson, director of the Department of Health and
Human Services' Office of Public Health Preparedness, told the panel that it
is possible to dry the smallpox virus and add stabilizers so it can persist
a long time in the air like anthrax, making its spread less predictable.
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And Dr. Don Millar, an environmental hazards expert who has worked with
the CDC in the past, argued that the federal government needs to pick a
course of action and stick with it.
"Whether the smallpox vaccine should be made available hinges on one
question: How big is the threat of a bioterrorism attack with smallpox?" he
said. "The government is behaving as though the threat is real."
He continued, "If there's no threat, they should quit demanding
expenditures. If there is a threat, then we need a good reason why we have
not made the vaccine available."
The current policy of withholding the vaccine "makes no sense," Millar
said.
"We have no shortage," he said. "If we withhold the vaccine, the decision
must be defended."
But Dr. Thomas Mack, a professor of preventative medicine with 40 years
experience in population outbreaks, said that the degree of threat must also
be weighed against the hazards of the vaccine itself. A key deterrent to
reinstating mass vaccinations, he said, is the short supply of vaccinia
immunoglobin (VIG) -- used to treat patients who develop complications
related to the vaccine.
The European data indicated that patients who developed complications and
were treated with VIG had a survival rate near 30 percent, while those who
did not receive the treatment had virtually no chance of survival.
"This is the single most dangerous live virus vaccine we have," Mack
said. "We don't need vaccination. We need ... personnel" to track reports of
the disease and react quickly.
Weighing the risks
Mass vaccinations carry with them other risks, as well, particularly to
those with compromised immune systems, such as HIV patients, cancer
patients, organ transplant patients and those with certain skin conditions.
In a government-funded study earlier this year, one-third of the 680
healthy young volunteers getting the vaccine had a reaction serious enough
to interfere with school or work.
However, smallpox itself is even more lethal. Before it was eradicated in
1980, about one-third of those affected died and others were left severely
scarred or blind.
But, several of the scientists said, mass communication is much more
effective now than it was as recently as 30 years ago, making it more
unlikely that an outbreak of smallpox could take hold.
"Look, if this happened today, we'd have CNN, who'd be screaming the
names of the persons who were exposed and if you'd been exposed to that
person you'd go out and get the vaccine," said Dr. J. Michael Lane, a former
CDC employee now working with the center on smallpox issues.
Health officials predict that by the end of 2002, there will be enough
vaccine available to inoculate every American.
In addition to Americans younger than 30 who were never vaccinated,
immunity against smallpox may be waning in Americans older than 30 who were
vaccinated -- and they may need to be revaccinated.
One study found that of 621 microbiologists in Maryland who received
smallpox revaccination between 1994 and 2001 as a precautionary measure,
only 6 percent were still immune from their previous vaccinations. Another
government-funded study is under way at St. Louis University to determine
how well smallpox immunity has endured.
The CDC already has a policy to use what is known as "ring vaccination"
in the unlikely event smallpox is ever released. Under this policy, those
infected and their close contacts would be vaccinated and quarantined to
reduce spread of the disease. The vaccine can stop the virus in its tracks
if given within three to five days of exposure.
About 59 percent of Americans surveyed by the Harvard School of Public
Health and the Robert Wood Johnson Foundation said they would get vaccinated
as a precaution if it was offered to them.
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