What is varicella (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. Most cases of chickenpox occur in persons less than 15 years old. Prior to the use of varicella vaccine, 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. 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 contact with an infected person to develop chickenpox.

What is the chickenpox illness like?

In children, chickenpox most commonly causes an illness that lasts about 5-10 days with high fever, severe itching, rash, dehydration or headache. In addition, about 1 child in 10 have a complication from chickenpox including infected skin lesions, other infections, dehydration from vomiting or diarrhea, exacerbation of asthma or more serious complications such as pneumonia.

Certain groups of persons are more likely to have more serious illness with complications. These include adults, infants, adolescents and people with weak immune systems from either illnesses or medications such a long-term steroids.

What are the serious complications of chickenpox?

Serious complications of chickenpox include bacterial infection which can involve many sites of the body including the skin, bone, lungs (pneumonia), joints and  blood. Other serious complications are due directly to the virus infection and include viral pneumonia, bleeding problems and infection of the brain (encephalitis). Many people are not aware that, before a vaccine was available, there were approximately 11,000 hospitalizations and 100 deaths from chickenpox in the U.S. every year . One child and one adult died each week.

Can a healthy person with varicella die from the disease?

Yes, many of the deaths and complications from chickenpox occur in previously healthy children and adults. Most of the healthy adults who died from chickenpox contracted the disease from their unvaccinated children.

Can chickenpox be prevented?

Yes, chickenpox can now be prevented by vaccination

Can you get chickenpox more than once?

Yes, but it is uncommon to do so. For most people, one infection is thought to confer lifelong immunity.

Chickenpox in children is usually not serious. Why not let children get the disease?

It is never possible to predict who will have a mild case of chickenpox and who will have a serious or even fetal case of disease. Now that      a safe and effective vaccine available, it is not worth taking this chance.

What is shingles?

Shingles, or herpes zoster, is caused by the chicken pox virus that remains in the nerve roots of all persons who had chickenpox and can come out in your body again years later to cause illness. 

Shingles is more common after the age of 50 and the risk increases with advancing age. Shingles causes numbness, itching or severe pain followed by clusters of blister-like lesions in a strip-like pattern on one side of your body. The pain can persist for weeks, months or years after the rash heals and is then known as post-herpetic neuralgia.

What should I do if I get shingles?

Contact your health care provider as soon as possible to discuss treatment with antiviral medications. These medications are most effective if given as soon as possible after rash onset.

Can someone who has been vaccinated for chickenpox develop shingles?

Yes. However, a study conducted among children with leukemia determined that after receiving the vaccine these children were much less likely to develop shingles than children who had prior natural chickenpox. Available information from healthy children and adults suggest that shingles is less common in vaccinated healthy persons compared with persons who have had natural chickenpox.

Why we should get the chickenpox vaccine ?

Chickenpox vaccine is the best way to prevent chickenpox, therefore protecting children and adults from the severe complications and death associated with the disease. Even with uncomplicated chickenpox cases, lost time from school and work and the cost of medications or treatment that may be needed can result in a significant cost for the family.

Who should be vaccinated with the chickenpox vaccine?

-All children between 12 and 18 months of age should have one dose of chickenpox vaccine. Children who have had chickenpox do not need the vaccine. No tests need to be administered to determine immune status - a parent's recollection of the disease is considered a reliable measure of previous infection and therefore immunity.

-Children between 19 months and their 13th birthday who have not had chickenpox should be vaccinated with a single dose.

-People 13 and older who have not had chickenpox should get two doses of the vaccine 4 to 8 weeks apart.

 How important is it for adults to be vaccinated for chickenpox?

All adults who have never had chickenpox should be vaccinated. Immunity is especially important for adolescents and adults who have close contact with persons at high risk for serious complications and for those who are likely to come in close contact with children.

Is the vaccine effective in preventing chickenpox all the time?

No vaccine is 100% effective in preventing disease. For chickenpox vaccine, about 8 to 9 out of every 10 persons vaccinated are completely protected from chickenpox. The vaccine almost always prevents against severe disease. If a vaccinated person does get chickenpox, it is usually a very mild case with fewer skin lesions (usually less than 50) lasting only  few days, no fever or low fever, and few other symptoms.

I don't think I have had chickenpox, but I am not sure. Is there a blood test available to determine whether or not I have had the disease?

Yes, a blood test is available to check immunity. Since 70% to 90% of adults who do not remember having chickenpox actually have protection in their blood when tested, blood testing before vaccination can be cost saving. Ask your doctor about this blood test. If it is not available, it is still safe to receive the vaccine even if you have previously had chickenpox.

Is there anyone who should not receive the chickenpox vaccine?

Yes, certain persons should not receive the chickenpox vaccine. These persons are those who:

Ever had a serious allergic reaction to chickenpox vaccine, neomycin, or gelatin (note: chickenpox vaccine does not contain egg), Are below 1 year of age, Now have moderate or serious illness (note: vaccine may be given to persons with a mild fever, cold or diarrhea), Are pregnant, Are unable to fight serious infections because of:

-any kind of cancer or cancer treatment with x-rays or drugs, (note: if your child has leukemia in remission he/she may be eligible to receive the vaccine, ask your doctor)

-a disease that depresses cellular immune function (note: if your child has HIV infection but has normal immune function he/she may receive the vaccine, ask your doctor)

-treatment with drugs such as long-term steroids

-Have received blood products(such as immune globulin or atransfusion) during the past five months.

If you are not sure, ask your doctor or nurse.

What problems can occur after chickenpox vaccination?

- Soreness, redness, or swelling where the shot was given is the most common side effect, occurring about 20% of the time.

- A very mild rash or several small bumps can result in about 1% to 4% of vaccine recipients. [NOTE: In very rare instances, it may be possible for someone who gets a rash from chickenpox vaccine to give vaccine strain chickenpox to another person. Persons developing a rash after vaccination should take extra precautions to avoid contact with anyone whose immune system is not working properly.]

- The vaccine may cause a mild fever 2 weeks after vaccination.

- A seizure (jerking and staring spell) usually caused by fever may occur in less than 1 in 1000 vaccine recipients. This may not be related to the vaccine.

Can the varicella vaccine virus be transmitted (caught from a person who was vaccinated)?

Yes; however, transmission of the varicella vaccine virus is very rare. It has only been documented in healthy persons on three occasions out of the 21 million doses of vaccine distributed. All three cases resulted in mild disease without complication.

My child was vaccinated 2-3 years ago and he/she developed a mild case of chickenpox this year. Why did this happen?

After vaccination, some persons (about 1 person in 10) do not develop enough protection to completely prevent them from developing chickenpox. When they come in close contact with a person with chickenpox, they may develop a mild case of disease with less than 50 spots or bumps. Compared with a case of chickenpox in an unvaccinated child, they will show very few signs of illness and may miss no school or only 1 or 2 days of school. Children who were vaccinated in their early childhood may have their first close contact with another child with chickenpox in child care or school settings several years after vaccination. This is why they may come down with mild chickenpox several years after they were vaccinated. This form of chickenpox is also called breakthrough disease.

Can a vaccinated person who develops a mild case of chickenpox still spread the disease?

Yes. Vaccinated persons who get this mild form of chickenpox may still spread the disease to others who are not protected. Therefore, these individuals should stay at home until the blisters have formed scabs or if there are no blisters present, until no new spots or bumps are forming.

My child has never had chickenpox and she just came into close contact with someone with chickenpox. Would receiving the vaccine now prevent her from getting chickenpox?

Yes, varicella vaccination may prevent or modify chickenpox if administered up to 3 days, and possibly 5 days, after a close exposure. If you or your child comes in close contact with a person with chickenpox and you have not had chickenpox or the vaccine, contact your health care provider for vaccination.

What home treatment are available for chickenpox?

Scratching the blisters may cause them to become infected. Therefore, keep fingernails trimmed short. Calamine lotion may help relieve some of the itching. Do not use aspirin or aspirin-containing products to relieve your child's fever. The use of aspirin has been associated with development of Reye syndrome (a severe disease affecting all organs, but most seriously affecting the liver and brain, that may cause death). Use non aspirin medications such as acetaminophen.