Varicella Virus Vaccine

While chickenpox is a mild infection, it can escalate into serious problems like brain inflammation, pneumonia, and a rare disease called Reye’s Syndrome if left untreated.


Varicella (also known as chickenpox) is a common childhood viral infection that is characterized by fever, rashes on the skin and an eruption of fluid-filled blisters. Most people who receive Varicella vaccine do not get chickenpox, or may only get a mild case that recovers quickly.

Chickenpox is a mild infection. However, it can be serious, and even fatal, in infants and in aging adults. Severe cases can lead to brain damage, breathing problems, skin infection, and death. In addition, a person who has suffered from chickenpox may develop shingles (also called zoster) later in life, which is characterized by skin infections, painful blisters, hearing and vision problems, and severe nerve pains that may last for months or years.

Chickenpox is a communicable disease, spread from person to person through the air, or by getting into contact with the fluid from a chickenpox blister. Varicella virus vaccine is administered subcutaneously to help prevent these diseases in aging adults and infants who are at least 12 months old. The vaccine works by exposing the recipient to small doses of the virus or a protein from the virus which causes the body to develop an immunity against the disease. It is important to note, however, that the vaccine does not treat an active infection that has already developed in the body. Like with any disease, varicella virus vaccine may not provide protection from chickenpox in every person.

Children under 13 years should receive two chickenpox doses: the first dose administered at age 12 through 15 months while the second dose should be administered at age four to six years. The second may be administered at an earlier age, provided it is given at least three months after the first dose.

Individuals aged 13 years and older who have never received a chickenpox vaccine or suffered from chickenpox should get two doses administered at least 28 days apart.

Chickenpox is especially crucial for the following groups of people:

  • Healthcare providers
  • Teachers
  • People who offer care for, or spend most of their time around people with weakened immune systems
  • Childcare workers
  • College students
  • Residents and workers in nursing homes and residential areas
  • Military personnel
  • Inmates and individuals working in correctional facilities
  • Non-expectant women of child-bearing age
  • Frequent international travelers
  • Adolescents and adults living with small children

Visit the CDC’s Immune (Protection) Against Chickenpox page to check if you are protected from chickenpox.

People with weakened immune systems who are not immunized against chickenpox may be considered for vaccination after talking with their healthcare providers. They include:

  • Individuals suffering from HIV/AIDS
  • Individuals on low or high doses of steroids
  • Individuals suffering from cancer, but whose disease is in remission

That said, it is important to note that varicella virus vaccine is not for everyone. The following groups of people should not get varicella vaccine or should wait before getting the vaccine.

  • Those who experienced life-threatening allergic reactions after a previous dose of chickenpox vaccine or a component of the vaccine, including the antibiotic neomycin or gelatin.
  • Those who are severely or moderately ill at the time the chickenpox vaccine is scheduled may have to wait until they recover before getting the shot.
  • Expectant women should wait to get the chickenpox vaccine after giving birth. Women should not conceive for one to three months after getting the chickenpox vaccine.
  • Individuals who had a recent blood transfusion or were given other blood products should consult their healthcare providers before getting the chickenpox vaccine.
  • People with active tuberculosis that is not being treated should not get the vaccine
  • People who have evidence of immunity against chickenpox do not have to get the vaccine
  • Finally, people with an infection or illness that is accompanied with fever should seek treatment before getting the vaccine.

The Center for Disease Control and Prevention (CDC) suggests that mothers may continue with breastfeeding after receiving varicella virus vaccine.

Conditions treated by varicella virus vaccine:

  • Chickenpox prevention
  • Zoster prevention

Type of medicine:

  • Vaccine

Side effects of varicella virus vaccine

As already mentioned, some people may experience life-threatening allergic reactions after receiving this vaccine.

Keep a record of any and all side effects that you experienced after receiving the varicella vaccine. When you receive a booster dose, be sure to tell your healthcare provider if the previous shots caused any side effects. Seek emergency medical help if you exhibit any of these allergic reactions after receiving the vaccination: difficulty breathing, hives, swelling of the face, tongue, lips or throat.

Call your healthcare provider when you experience any of the following adverse side effects of varicella virus disease.

  • A persistent cough, breathing difficulty and a tight feeling in your chest
  • Seizure (convulsions or black-outs)
  • Easy bruising and bleeding, and unusual fatigue
  • Behavior changes
  • Severe fever within a few hours of weeks after the vaccine

Some of the vaccine’s mild side effects include the following:

  • Low fever
  • Mild rashes on the skin
  • Pain, redness or swelling on the spot where the shot was given
  • Stuffy or runny nose, sore throat, and occasional cough
  • A mild headache and tired feeling
  • Muscle and joint pain
  • Sleep problems (insomnia)
  • Nausea, diarrhea, stomach pain and vomiting

This list is not complete, and some people may experience other side effects. Call your doctor about any side effect you experience after the vaccine. You may also report the vaccine’s side effects to the US Department of Health and Human Services at 1-800-822-7967.

Varicella virus vaccine dosage

Varicella virus vaccine (brand name Varivax) is administered as an injection (shot) under the skin. The vaccine is given at the doctor’s office, pharmacy or clinic setting. Any person who has never suffered from chickenpox or who has never been vaccinated should receive 1-2 doses of varicella vaccine.

As already indicated, children aged 1 to 2 years old should receive 2 doses. The second dose, also called the booster dose, may be administered 3 months after the first dose. However, it may be delayed until the child is 4 to 6 years old.

People who at 13 years and older, and have never suffered from chickenpox nor received varicella virus vaccine, should receive 2 doses 4 to 8 weeks apart. Your second dose’s schedule may differ from these guidelines. Follow your doctor’s recommendations or the schedule recommended by the health department in your area. Again, both doses should be administered subcutaneously.

Varicella virus vaccine can cause false results on a skin test for tuberculosis. Inform your doctor, during treatment, if you received a varicella virus vaccine within the past 3-7 weeks. Varicella virus vaccine overdose is unlikely to occur.

Get in touch with your doctor if you miss the booster dose or fall behind schedule. Arrange to get the next dose as soon as possible. You do not have to start over. Ensure that you receive all recommended varicella virus vaccines as you may not be fully protected against chickenpox if you do not receive the full dose.

Getting varicella virus vaccine after exposure to chickenpox

If you have no immunity against chickenpox and are in contact with someone with the chickenpox or shingles, discuss with your doctors about getting vaccinated. It is advisable that you get chickenpox vaccine within three to five days after being exposed. You need two doses: the first dose, and the second (booster) dose. Getting the vaccine after coming into contact with someone with chickenpox can:-

  • Prevent you from falling sick or make the disease less serious
  • Protect you from chickenpox in the future should you be exposed

Your doctor may prescribe a medication to make chickenpox less severe. This is especially important for people who get into contact with the virus and do not have immunity to the disease or are not eligible for vaccination.

Type of varicella virus vaccine - Varivax

This is a live virus used to prevent varicella (chickenpox) infection. The vaccine is refrigerated and works by prompting the body to produce its own protection against chickenpox. It does this by boosting the antibodies’ ability to fight varicella virus. Thus, when a vaccinated person gets exposed to the virus, the body’s defense mechanism is usually ready to destroy it.

Varivax is licensed for administration in toddlers 12-months and older, adolescents and adults. It can be given to children for their routine double dose of chickenpox vaccine at 12 months through 15 months and four years through six years old.

Things to do after Varivax injection

If you are 13 years of age or older, be sure to keep your appointment for the follow-up dose. This is essential to ensure that the vaccine has the best chance of protecting you against chickenpox virus.

Avoid getting pregnant for at least three months after Varivax vaccination. Also, inform your doctor about Varivax vaccination if you are scheduled for immune globulin (including varicella zoster globulin) within 2 months from the vaccination.

Avoid coming into contact with the following people for at least six weeks after your Varivax injection:

  • People with weak immune systems
  • Newborn babies
  • Expectant women

Finally, avoid taking Aspirin or salicylate medicines for at least six weeks after receiving Varivax vaccination.

Varicella virus vaccine interactions

For at least six weeks are getting your varicella virus vaccine, avoid coming into contact with expectant mothers who have never suffered from chickenpox, newborn infants, and anyone with a weak immune system. There is a chance that you may pass the virus to a person with no immunity to chickenpox or one with a weak immune system.

For individuals under 18 years old: Avoid taking salicylate medications such as kaopectate, aspirin, Pamprin Cramp Formula, KneeRelief, Pepto-Bismol, Trilisate, Tricosal and others for at least six weeks after getting varicella virus vaccine. Salicylates are known to cause Reye’s Syndrome, a serious and at times fatal condition in children and teenagers suffering from chickenpox, and the varicella virus vaccine exposes you to small amounts of the chickenpox virus.

There may be other drugs that interact with varicella virus vaccine. Talk to your doctor about all the medications you are currently on as well as the ones you recently used or are planning to start during your varicella vaccine and booster schedules.

Varicella virus vaccine may also interact with the following medications:

  • Corticosteroids such as prednisone and dexamethasone
  • Antineoplastic or chemotherapy medications like methotrexate
  • Immune globulin
  • Dimethyl fumarate
  • Immunosuppressants such as cyclosporine, azathioprine, hydroxychloroquine, tacrolimus, and leflunomide.
  • Most liver vaccines
  • Varicella zoster immune globulin

Talk to your doctor prior to getting varicella virus vaccine if you are taking any of these medications. Depending on your specific circumstances, your doctor may ask you to do any of the following:

  • Stop taking the medications for some time
  • Change medications weeks leading to and after the vaccination
  • Change how you are taking the medications
  • Leave everything as is

An interaction between medications does not always mean that you have to stop taking any of the medications concurrently, especially if the interactions are mild or non-life threatening. Talk to your healthcare provider about how you should manage drug interactions.

Medications other than those mentioned above may interact with this vaccine. Disclose to your doctor or prescriber all prescription as well as over-the-counter (non-prescription), supplements and herbal medications you are currently taking. Since alcohol, caffeine, street drugs and nicotine from cigarettes affect the action of most medications, you should let your prescriber know if you are on any of these.

Varicella virus vaccine warnings

Like with any medication, before getting varicella virus vaccine, be sure to inform your doctor of all medical conditions and allergies you may have, all the medications you are taking, whether you are expectant or are breastfeeding, or any other important facts about your life. That said, the following factors may affect how you should use this vaccine.

Duration of protection

It is not yet clear how long varicella virus vaccine’s protective effects against chickenpox will last


Your doctor may decide to delay this vaccine if you are suffering from acute infection or fever. Mild infections that are not accompanied with fever, such as colds, usually do not require delay of the vaccine

Medical conditions

Varicella virus vaccine should not be administered for at least five months following a blood or plasma transfusion.

Salicylate therapy

People on varicella virus vaccine should not use salicylates like ASA for at least six weeks after vaccination as they may be at a higher risk of contracting Reye’s syndrome. Children and adolescents should avoid salicylates unless advised otherwise by the doctor.


Rarely do healthy people taking varicella vaccine, and who develops varicella-like rashes due to vaccination, may transmit the vaccine virus to healthy people during contact. However, people taking this vaccine should try as much as possible to avoid getting into close contact with susceptible high-risk people (like those whose immunity is compromised, expectant mothers without a history of chickenpox and newborns to mothers without a history of chickenpox) for at least six weeks after receiving the vaccine.


Varicella virus vaccine is not to be administered during pregnancy. In addition, pregnancy should be avoided for at least three months after vaccination.


It is not clear if varicella vaccine can be passed through breast milk. Talk to your doctor about whether or not you should continue breastfeeding after getting the vaccine.


The effectiveness and safety of using this medication is yet to be established for infants less than 12 months old. It is, therefore, not recommended for children under 12 months old.

Important note:

Vaccination with varicella virus vaccine does not guarantee complete protection of healthy or susceptible from chickenpox and zoster. Some people have reported chickenpox infection after vaccination. However, the severity of the infection in people who have received the vaccine tend to be mild.

Varicella virus storage

The vaccine is administered in the doctor’s office hence will not be stored at home. That said, like with any other drug, it should be stored in the original bottle in a cool and dry place away from direct sunlight. All expired vaccines should be disposed of appropriately.


Chickenpox is a very contagious disease that is caused by the varicella-zoster virus (VZV). It is characterized by itching, blister-like rashes, fatigue and mild to severe fever. The FDA has approved Varivax as a subcutaneous Chickenpox vaccine in the United States.

The Center for Disease Control recommends two doses of vaccine to prevent chickenpox in children, teenagers and adults. Children should receive the first dose at 12 to 15 months and the second (booster) dose at four through six years old.

Varicella virus vaccine is used to help prevent varicella virus infection. While chickenpox is not a life-threatening disease, it can cause serious illness in people who have weak immunity or who have never been vaccinated against the disease. Serious, rarely fatal, problems such as inflammation of the brain or liver and pneumonia may occur as a result of chickenpox infection. First time infections in adults may be very severe. Chickenpox may also cause very serious liver or brain condition called Reye’s Syndrome in younger children and teenagers. It may also cause harm to the unborn child if you are infected while pregnant.

Vaccination during childhood may help prevent chickenpox infection and the problems associated with it. The virus in the varicella vaccine is alive, but in its weak (attenuated) form and, thus, has a reduced ability to cause illness. It works by aiding the body in production of immunity that prevents you from getting chickenpox, or by lessening the severity of the infection. As with any vaccine, varicella virus vaccine may not fully protect you from getting chickenpox. People who catch chickenpox after the vaccination usually have mild cases that are characterized by fewer blisters, less severe fevers, and faster recoveries. The vaccine is, however, not recommended for people with weakened immunity, those treating any form of cancer, as well as expectant and nursing mothers.

Last Reviewed:
December 24, 2017
Last Updated:
December 22, 2017
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