April 26, 2002
MEDIA CONTACT: Trent Stockton
PHONE: 410-955-8665
E-MAIL:
tstockt1@jhmi.edu
Need, Potential for Hepatitis C Vaccine Highlighted by Hopkins Study
"Our findings suggest that humans can acquire immunity
that protects against the disease caused by hepatitis C virus."
Humans may be able to develop immunity to hepatitis C virus, according to a
study by Hopkins researchers published in the April 26 issue of The Lancet,
findings that add to a growing body of evidence that immunity to the virus can
be acquired. The findings are important because no vaccines exist for
preventing hepatitis C in humans although preliminary vaccine research in
primates appears promising.
Other studies in chimpanzees demonstrate that although animals who were
previously infected or vaccinated could be infected with hepatitis C virus,
those infections were less likely to persist compared to animals infected for
the first time, according to David L. Thomas, associate professor of medicine
at Hopkins and lead author of the study.
"We found the same in humans, suggesting that humans can acquire immunity
that protects against hepatitis C virus persistence," says Thomas. "If this is
indeed the case, it suggests that vaccines can be used to protect us from the
long-term complications of hepatitis C infection, like liver cirrhosis and
liver cancer."
In their study of injecting drug users from Baltimore, Md., Thomas,
co-author Shruti Mehta, M.P.H., and colleagues identified 164 people whose
blood tests revealed no evidence of previous hepatitis C infection, and 98
people who had been infected in the past but were not currently infected with
the virus. They compared the incidence and persistence of infection in these
two groups over four consecutive six-month periods.
People previously infected were half as likely to develop new infections
compared to those who had not been previously infected (12% compared to 21%,
respectively). Among HIV-1-negative people, those previously infected were 12
times less likely to develop persistent infection than people infected for the
first time .
"The medical consequences of hepatitis C virus are tremendous," says
Thomas. "Our findings indicate that vaccines should be developed to reduce the
burden of liver disease associated with hepatitis C infection."
Close to 4 million people in the United States and 170 million people
worldwide have been infected with the hepatitis C virus. Eighty-five percent
of those infected develop persistent infection and are at risk of serious
complications such as liver cirrhosis and liver cancer, according to Thomas.
Other authors of the study are Stephanie Strathdee, Ph.D., Andrea Cox,
M.D., Xiao-Hong Wang, M.D., Qing Mao, M.D., and Stuart Ray, M.D., all from
Johns Hopkins; Donald Hoover, Ph.D., of Rutgers University, and David Vlahov,
Ph.D., of the New York Academy of Medicine. The study was funded by the
National Institute on Drug Abuse and the National Institute of Allergy and
Infectious Disease.
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LEGAL ADVICE. THE DECISION WHETHER OR NOT TO VACCINATE IS AN IMPORTANT AND
COMPLEX ISSUE AND SHOULD BE MADE BY YOU, AND YOU ALONE, IN CONSULTATION WITH
YOUR HEALTH CARE PROVIDER.
"A foolish faith in authority is the worst enemy of truth."
-- Albert Einstein, letter to a friend, 1901
"I know of no safe depository of the ultimate powers of the society but the people themselves, and if we think them not enlightened enough to exercise control with a wholesome discretion, the remedy is not to take it from them, but to inform their discretion by education."
-- Thomas Jefferson, letter to William C. Jarvis, September 28, 1820
"What's the point of vaccination if it doesn't protect you from the unvaccinated?"
-- Sandy Gottstein
"Who gets to decide what the greater good is and how many will be sacrificed to it?"