Chickenpox vaccine is the best way to prevent chickenpox. Vaccination not only
protects vaccinated persons, it also reduces the risk for exposure in the
community for persons unable to be vaccinated because of illness or other
conditions, including those who may be at greater risk for severe disease. While
no vaccine is 100% effective in preventing disease, the chickenpox vaccine is
very effective: about 8 to 9 of every 10 people who are vaccinated are
completely protected from chickenpox. In addition, the vaccine almost always
prevents against severe disease. If a vaccinated person does get chickenpox, it
is usually a very mild case lasting only a few days and involving fewer skin
lesions (usually less than 50), mild or no fever, and few other symptoms.
Fact Sheet on the Chicken
Answers about Chickenpox
Chickenpox is an infectious disease caused by the varicella-zoster virus, which
results in a blister-like rash, itching, tiredness, and fever. The rash appears
first on the trunk and face, but can spread over the entire body causing between
250 to 500 itchy blisters in unvaccinated persons. Prior to use of the varicella
vaccine, most cases of chickenpox occurred in persons younger than 15 years of
age and the disease had annual cycles, peaking in the spring of each year.
How do you get chickenpox?
Chickenpox is highly infectious and spreads from person to person by direct
contact or through the air from an infected person’s coughing or sneezing or
from aerosolization of virus from skin lesions. A person with chickenpox is
contagious 1-2 days before the rash appears and until all blisters have formed
scabs. It takes from 10-21 days after exposure for someone to develop
Can you get chickenpox if you've
Yes. About 15%–20% of people who have received one dose of chickenpox vaccine do
still get chickenpox if they are exposed, but their disease is usually mild.
Vaccinated persons who get chickenpox generally have fewer than 50 spots or
bumps, which may resemble bug bites more than typical, fluid-filled chickenpox
blisters. In 2006, the Advisory Committee on Immunization Practices (ACIP) voted
to recommend routine two-dose varicella vaccination for children. In one study,
children who received two doses of the chickenpox vaccine were three times less
likely to get chickenpox than individuals who have had only one dose.
What is the chickenpox illness like?
In unvaccinated children, chickenpox most commonly causes an illness that lasts
about 5-10 days. Children usually miss 5 or 6 days of school or childcare due to
their chickenpox and have symptoms such as high fever, severe itching, an
uncomfortable rash, and dehydration or headache. In addition, about 1 in 10
unvaccinated children who get the disease will have a complication from
chickenpox serious enough to visit a health-care provider. These complications
include infected skin lesions, other infections, dehydration from vomiting or
diarrhea, or more serious complications such as pneumonia and encephalitis. In
vaccinated children, chickenpox illness is typically mild, producing no symptoms
at all other than a few red bumps. However, about 25% to 30% of vaccinated
children who get the disease will develop illness as serious as unvaccinated
Certain groups of people are more likely to have more severe illness with
serious complications. These include adults, infants, adolescents, and people
whose immune systems have been weakened because of illness or medications such
as long-term use of steroids.
What are the serious complications
Serious complications from chickenpox include bacterial infections which can
involve many sites of the body including the skin, tissues under the skin, bone,
lungs (pneumonia), joints, and blood. Other serious complications are due
directly to infection with the varicella-zoster virus and include viral
pneumonia, bleeding problems, and infection of the brain (encephalitis). Many
people are not aware that before a vaccine was available approximately 10,600
persons were hospitalized and 100 to 150 died as a result of chickenpox in the
U.S. every year.
Can a healthy person who gets
varicella die from the disease?
Yes. Many of the deaths and complications from chickenpox occur in previously
healthy children and adults. From 1990 to 1994, before a vaccine was available,
about 50 children and 50 adults died from chickenpox every year; most of these
persons were healthy or did not have a medical illness (such as cancer) that
placed them at higher risk of getting severe chickenpox. Since 1999, states have
been encouraged to report chickenpox deaths to CDC. These reports have shown
that some deaths from chickenpox continue to occur in healthy, unvaccinated
children and adults. Most of the healthy adults who died from chickenpox
contracted the disease from their unvaccinated children.
Can chickenpox be prevented?
Yes, vaccination with the recommended two-doses of varicella vaccine prevents
chickenpox in most people.
Can you get chickenpox more than
Yes, but such occurrences are uncommon. For most people, one infection appears
to confer lifelong immunity.
Chickenpox in children is usually
not serious. Why not let children get the disease?
It is not possible to predict who will have a mild case of chickenpox and who
will have a serious or even deadly case of disease. Now that there is a safe and
effective vaccine, it is not worth taking this chance.
Pictures of the chicken pox in children and adults are at the CDC website:
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