Chickenpox (Varicella)
A highly contagious viral illness. CDC lists international travellers as a priority group for vaccination if not already immune. Most people vaccinated as children or who've had chickenpox are protected for life.
What it is
Chickenpox is a highly contagious virus that causes an itchy rash with blisters, plus fever and tiredness. It is usually mild in children but can be more serious in adults.
How it spreads
Through the air from coughs and sneezes, and through direct contact with the blisters.
Dosing & timing
- Primary series
- Two doses, at least 28 days apart for adolescents and adults. Children get doses at 12 to 15 months and again at 4 to 6 years.
- Boosters
- Two documented doses protect most people for life.
- Before you travel
- Ideally complete both doses before travel, but partial protection starts after the first dose.
Who should consider it
Most adults are protected from childhood vaccination or from having had chickenpox. CDC lists international travellers as a priority group for vaccination if you do not have evidence of immunity. If you have no records and never had chickenpox, talk to a travel doctor about getting protected.
Side effects and safety
Common (most resolve in a day or two)
- Soreness where the shot was given
- Mild fever
- Mild rash near the injection site
Serious but rare
- Severe allergic reaction (very rare)
Who should not get it
Skip it if you have a severely weakened immune system, are pregnant, or have had a severe allergic reaction to a previous dose. This is a live vaccine, so timing matters around pregnancy and immune-suppressing treatments.
Common questions
I had chickenpox as a child — do I need the vaccine?
No. A clear history of chickenpox counts as immunity. Most adults are already protected.
What if I'm not sure whether I had it?
A blood test can check for immunity, or your doctor may simply give you the vaccine. There is no harm in vaccinating someone who is already immune.
Why does CDC list travellers as a priority group?
Vaccination rates vary by country, so you may meet more unvaccinated people abroad. International travel is a common context for adult chickenpox cases.
Plan ahead: Talk to a travel health doctor 4 to 6 weeks before departure if you are unsure about your chickenpox immunity.
Source: CDC — Chickenpox (Varicella).
Disclaimer:This information is for general guidance only, based on CDC Travelers' Health. It does not replace advice from a qualified travel health professional. Consult a doctor 4–6 weeks before your trip.