The Basics
What Causes Chickenpox?
Chickenpox is a highly contagious disease caused by the Varicella-Soster Virus (VSV). It is characterised by an itchy, blister-like rash that eventually turns into scabs. The virus spreads easily through the air (coughing and sneezing) or through direct contact with the fluid from the blisters. While usually a mild illness in children, it can be much more severe in adults, pregnant women, and those with weakened immune systems.
Vaccination Overview
The Chickenpox (Varicella) Vaccine
| Feature | Details |
| Number of Doses | A full course consists of two doses. |
| Schedule | The second dose is usually given 4 to 8 weeks after the first dose. |
| When to get it | Ideally before children start school, or for adults who have never had the disease. |
| The Booster | A 2-dose course provides over 90% protection for life. Routine boosters are not currently required. |
| How it is given | Administered as a subcutaneous injection, usually in the upper arm. |
| Suitable Age | Suitable for children 12 months of age and older and adults. |
Safety & Side Effects
What to Expect After Vaccination
The chickenpox vaccine is safe and effective. Side effects are generally mild:
Local Reaction: Soreness, redness, or swelling at the injection site.
Mild Rash: About 1 in 10 people may develop a very mild, non-contagious chickenpox-like rash (usually just a few spots) near the injection site up to a month later.
General: A low-grade fever or feeling slightly tired.
Symptoms of Diphtheria
Symptoms of Chickenpox
Symptoms usually appear 10 to 21 days after exposure. You are contagious from 1 to 2 days before the rash starts until all blisters have scabbed over.
The Rash: Itchy red spots that fill with fluid (blisters), which then burst and crust over.
Fever: A high temperature that often starts a day or two before the rash.
General Malaise: Feeling tired, irritable, and a loss of appetite.
Aches: Headache and muscle aches are common in older children and adults.
Additional Precautions
Protecting High-Risk Groups
Because chickenpox can be dangerous for certain groups, please follow these precautions:
Pregnancy: If you are pregnant and have never had chickenpox or the vaccine, avoid anyone who is currently infected.
Shingles Connection: The virus that causes chickenpox stays in your body and can reactivate years later as Shingles. Vaccinating against chickenpox prevents the initial infection.
Avoid Aspirin: Do not give aspirin to children with chickenpox, as it can lead to a serious condition called Reye’s Syndrome. Use paracetamol for fevers instead.
Isolation: Keep infected children home until every single spot has crusted over (usually 5 to 7 days after the rash starts).
Others Services
FAQ
My child was exposed yesterday. Is it too late for the vaccine?
No! If given within 3 to 5 days of exposure, the vaccine can often prevent the disease entirely or make the symptoms much milder.
Why isn't this vaccine free on the NHS for everyone?
In the UK, the vaccine is currently only routine for those in close contact with vulnerable people. However, many parents choose to have it privately to avoid their children suffering and to prevent parents from having to take a week off work.
Medical Disclaimer
The information provided on this website is for educational and informational purposes only and is not intended as medical advice, diagnosis, or treatment. While we strive to provide accurate health information, it is not a substitute for the professional judgment of a healthcare provider. Always seek the advice of your physician or other qualified health professional with any questions you may have regarding a medical condition or vaccination schedule. Never disregard professional medical advice or delay seeking it because of something you have read on this website.