What should you know about being immune to varicella?

Varicella is the virus behind chickenpox. Immunity can develop after the body responds to the virus during an earlier infection or after a chickenpox vaccination. A record of vaccination, a clinician's assessment, or a blood test may help establish your status, depending on why the information is needed.

Protection against chickenpox does not remove the varicella-zoster virus from the body after an earlier infection. The virus can remain inactive in nerve tissue and later reactivate as shingles. A new blistering rash is therefore worth discussing with a clinician, even if you remember having chickenpox before.

Check your immunisation record and tell a healthcare professional whether you have had chickenpox, a varicella vaccine, or an antibody test. This is especially relevant before pregnancy, immune-suppressing treatment, or close contact with someone who may have chickenpox.

If you develop an itchy, fluid-filled rash or fever, avoid close contact with people who are pregnant, newborn, or immunocompromised until you have received advice. Do not scratch blisters; gentle cleansing and trimmed nails can reduce skin injury. A GP consultation can clarify whether the rash fits chickenpox, shingles, or another cause. Treatment decisions may include antiviral treatment or antihistamine treatment when clinically appropriate.

Seek prompt medical advice for a new blistering rash if you are pregnant, have a weakened immune system, are caring for a newborn, or recently had close contact with someone with chickenpox. Early assessment can help identify people who may need time-sensitive treatment or prevention.

Arrange urgent assessment for breathing difficulty, severe headache, confusion, marked drowsiness, dehydration, rapidly worsening skin redness, or blisters near the eye. Fever with a spreading blistering rash also warrants medical review. You can read more about fever and skin blisters while arranging advice.

Ask which evidence confirms your immunity, whether you need vaccination or testing, and how to respond if you are exposed to chickenpox. If you have a rash, ask whether it is more consistent with chickenpox, shingles, or another skin condition, and which symptoms should trigger immediate help.