Children usually receive the chickenpox vaccine starting at about 12 months, but the schedule depends on where they live. In the United States, the Centers for Disease Control and Prevention (CDC) recommends one dose at 12–15 months and a second at 4–6 years. Some countries use different ages or a combined vaccine, so follow your local immunization schedule and ask a healthcare professional about missed doses.
Chickenpox, also called varicella, is a contagious viral infection that can cause an itchy rash and fever. Although many children recover without serious problems, complications can occur. Vaccination helps protect children against chickenpox and reduces the risk of serious illness. Knowing when the doses are due, whether a missed dose can be caught up, and which medical conditions may affect vaccination can help parents plan their child's immunizations.
What is the usual age for the chickenpox vaccine?
The recommended age depends on the country's childhood immunization program. In the United States, the CDC recommends a two-dose chickenpox vaccination series for children:
- First dose: At 12–15 months of age.
- Second dose: At 4–6 years of age, usually before the child starts school.
The second dose provides additional protection. Children who have received only one dose may still develop chickenpox, so completing the recommended series is important. The exact timing of each dose should follow local guidance, particularly if a child received an earlier dose outside the usual schedule.
Does the vaccination schedule differ by country?
Yes. Countries establish vaccination schedules according to their public health policies and immunization programs. The ages at which children receive the chickenpox vaccine, the number of routine doses, and the availability of combination vaccines can therefore differ.
For example, the current National Health Service (NHS) guidance describes a childhood schedule in which children are offered the combined measles, mumps, rubella, and varicella vaccine, known as MMRV, at 12 months and 18 months. The NHS also describes vaccination arrangements for certain older children.
The World Health Organization's 2025 position paper on varicella vaccines provides evidence and recommendations to inform national immunization programs. It is therefore important to follow the schedule applicable to your child's country rather than assuming that the US or UK timetable applies everywhere.
Can a child receive the chickenpox vaccine after the recommended age?
Yes. Children who missed a scheduled dose may still be eligible for vaccination through a catch-up schedule. There is generally no need to assume that a delay means the entire series must be restarted. A healthcare professional can check the vaccination record and determine which dose is due and when it should be given.
In the United States, children younger than 13 years who need catch-up vaccination are generally recommended to receive two doses, with the interval determined by their age and previous vaccinations. Adolescents aged 13 years or older who have no evidence of immunity generally need two doses separated by 4–8 weeks.
The CDC's varicella vaccine recommendations provide specific guidance for catch-up doses and older children. Because national recommendations differ, families should have the vaccination dates reviewed by their local healthcare provider before arranging a missed dose.
What if a child has already had chickenpox?
A child who has had chickenpox may already have immunity to the infection. However, parents should tell the healthcare professional about the illness rather than deciding on their own that vaccination is unnecessary. A rash that was assumed to be chickenpox may have had another cause, and the reliability of the history matters.
Under US guidance, a healthcare professional's verified diagnosis or other accepted evidence of immunity can affect whether additional vaccination is recommended. If the illness was never confirmed, the clinician can review the child's history and vaccination record to determine the appropriate next step.
Can the chickenpox vaccine be given with other childhood vaccines?
Yes. The chickenpox vaccine can be administered during the same visit as other recommended childhood vaccines when the applicable schedule permits it. Depending on the country and the child's age, it may be given as a separate injection or as part of the combined MMRV vaccine, which protects against measles, mumps, rubella, and varicella.
A combination vaccine can reduce the number of separate injections a child receives. However, the choice between a combined vaccine and separate injections may depend on the child's age, medical history, local recommendations, and the healthcare professional's advice.
When should vaccination be delayed or avoided?
Most eligible children can receive the chickenpox vaccine according to the recommended schedule. However, some medical conditions and treatments require additional assessment because the routinely used chickenpox vaccine contains a weakened form of the virus.
Before vaccination, tell the healthcare professional if your child:
- Has a condition that severely weakens the immune system.
- Is receiving chemotherapy or certain medicines that suppress immune function.
- Has experienced a serious allergic reaction to a previous chickenpox vaccine dose or one of its ingredients.
- Has recently received certain blood products or antibody-containing treatments that may affect vaccine timing.
These circumstances do not all have the same implications. Depending on the situation, vaccination may be unsuitable or may need to be postponed. The clinician can review the child's medical history and current medicines before deciding how to proceed. Do not delay an entire vaccination series without discussing the reason with a healthcare professional.
What if a child has been exposed to chickenpox before vaccination?
If your child has been in close contact with someone who has chickenpox and is not fully vaccinated, contact a healthcare professional promptly. Do not wait for symptoms to appear before asking for advice about vaccination.
According to the CDC's guidance on varicella vaccination, an eligible person without evidence of immunity should ideally receive the vaccine within 3–5 days after exposure. Vaccination during this period may prevent chickenpox or make the illness less severe. Vaccination may still be useful after that window for future protection, but not everyone exposed to the virus can receive the vaccine safely.
If the exposed child has a weakened immune system or another condition that may make chickenpox more dangerous, seek prompt medical advice. A healthcare professional can assess whether vaccination or another preventive approach is appropriate.
What side effects can occur after the chickenpox vaccine?
Most side effects are mild and settle without special treatment. They may include soreness, redness, or swelling where the injection was given, a fever, or a mild rash. Not every child experiences these effects.
The CDC's chickenpox vaccine information statement explains the expected benefits and possible risks of vaccination. Follow the instructions provided by your vaccination clinic, and contact a healthcare professional if your child develops symptoms that are concerning, persistent, or worsening. Seek emergency care for signs of a serious allergic reaction, such as difficulty breathing or swelling of the throat.
How can parents keep track of their child's doses?
Keep a record of each vaccination, including the date and the vaccine given. Bring this record to routine checkups and when visiting a different healthcare provider. If the record is incomplete or unavailable, the clinic can help determine whether reliable documentation exists and what steps are recommended.
Parents should also check the timing of upcoming childhood immunizations before school entry or other important transitions. If a dose is overdue, ask the clinic about catch-up vaccination instead of assuming the child is too old to receive it.