Vaccine Stops Hepatitis B for 15 Years
Longer Protection May Reduce Need for Booster Shots
Feb. 28, 2005 -- The hepatitisB vaccine
works for at least 15 years -- longer than once thought.
The vaccine thwarts the virus that causes hepatitis B, a liver disease that
can lead to liver cirrhosis or cancer. Most countries
include the vaccine in their infant immunization programs. It's given in a
series of three shots and was known to protect against hepatitis B for five to
10 years. But no one knew if it worked beyond that point.
Now, researchers have an answer. The vaccine "strongly protected against
[hepatitis B] infection for at least 15 years in all age groups," they
However, the benefits faded fastest in people vaccinated when they were 4
years old or younger. Researchers will keep an eye on those patients to see if
they need additional doses of the vaccine or booster shots in the future.
The news comes from a study of Alaska natives, who have high rates of
hepatitis B, with most cases starting in early childhood.
A total of 1,578 people participated.
In the early 1980s, participants were fully vaccinated against hepatitis B.
All were at least six months old, and some were in their 20s or older.
After 15 years, the researchers were still in touch with almost half of the
group. The vaccine's protection against infection was still going strong in 84%
of those people.
Vaccine Lasts Longer After 5th Birthday
The vaccine's effectiveness waned the most in people vaccinated before their
fifth birthday. "It is important that we continue to follow this group in
order to determine when and if booster doses will be necessary," says the
The report comes from researchers including Brian McMahon, MD, of the CDC's
Arctic Investigations Program. The study appears in the March 1 edition of the
Annals of Internal Medicine.
The finding may spare patients from needless booster shots, says Ding-Shinn
Chen, MD, of National Taiwan University's medical school.
"Unless continued follow-up and surveillance show clinically significant
rates of infection for adolescents who were vaccinated as children, booster
vaccinations will be wasteful," writes Chen in an Annals of Internal
Hepatitis B can be
spread through contact with infected body fluids, such as through sexual
contact or shared needles. It can also be spread from an infected mother to her
newborn at the time of birth.
The vaccine is the one of the most effective ways to prevent hepatitis B
infection. It's most effective when all three shots of the vaccine are
For further protection, use a condom when you have sex, don't share needles,
wear plastic or latex gloves if you have to touch blood, and don't share
toothbrushes or razors.