Varicella Vaccination

What is the varicella vaccine?

The varicella vaccine is designed to protect against chickenpox, a common and highly contagious disease caused by the varicella-zoster virus (VZV).

Chickenpox is a highly contagious disease that causes a blister-like rash, itching, fever, and tiredness. It spreads through direct contact with the rash, saliva or mucus of an infected person. It can also spread through the air when someone with chickenpox coughs or sneezes.

How the varicella vaccine works

The varicella vaccine contains a live but weakened form of the varicella-zoster virus. Once introduced into the body, it prompts the immune system to respond by producing antibodies to fight off the virus without causing the disease itself.

This process establishes immunity, which helps protect against future virus exposure.

Why do you need the varicella vaccine?

Chickenpox is typically a mild illness but can sometimes cause serious complications, such as bacterial infections, pneumonia, inflammation of the brain, and even death.

By getting vaccinated, individuals can significantly reduce the risk of contracting chickenpox and its associated complications.

Additionally, vaccination is crucial in protecting those vulnerable or unable to be vaccinated, such as newborns, individuals with certain medical conditions, or people with weakened immune systems.

When do you need the varicella vaccine?

In accordance with Singapore's National Childhood Immunisation Schedule (NCIS), all children should receive 2 doses of the varicella vaccine starting at 12 months of age, with a minimum interval of 3 months between doses.

Adults aged 18 and above who have not previously received the varicella vaccine or lack evidence of past infection or immunity should follow the Singapore National Adult Immunisation Schedule (NAIS) and receive 2 doses, with the second administered within 4 – 8 weeks of the first dose.

Who should not receive the varicella vaccine?

You should not receive the varicella vaccine if you:

Have had a severe allergic reaction to a previous dose of the varicella vaccine or any component of the vaccine, including gelatin or neomycin
Are breastfeeding, pregnant or planning to become pregnant within the next month
Have a weakened immune system due to conditions such as leukaemia, HIV/AIDS, or by taking medications like steroids
Are undergoing cancer treatment with radiation or drugs
Have recently received a blood transfusion or bone marrow transplant

How do you prepare for the varicella vaccine?

Discuss your medical history with your doctor, including past illnesses and allergic reactions
Inform your doctor if you are taking any medications, including over-the-counter medications
Inform your doctor if you are pregnant or have a weakened immune system
Plan to avoid getting pregnant for at least 1 month after getting the varicella vaccine

What can you expect when getting the varicella vaccine?

The varicella vaccine is usually given as an injection in the upper arm. Your doctor may ask you to stay for 15 – 20 minutes after receiving the vaccine to watch for any immediate allergic reactions.

What are the common side effects of the varicella vaccine?

The most commonly reported side effects include:

Mild pain, redness, or swelling at the injection site
Skin rash
Temporary pain or stiffness in the joints
Low-grade fever

What are the serious side effects that require medical attention?

While serious side effects are rare, they can occur. See a doctor if you experience:

Severe allergic reaction (hives, difficulty breathing, wheezing, swelling of the face, lips, tongue, or throat)
A fast heartbeat or dizziness
Paleness
Weakness
Seizure
High fever
Chickenpox-like rash

If any of these symptoms occur, seek medical attention immediately.