What is Varicella (Chickenpox)?
Varicella (Chickenpox) is a highly contagious acute viral disease caused by the Varicella virus. While chickenpox is generally a mild disease in children, with a generalised vesicular rash and fever, complications such as secondary skin infections, pneumonia and encephalitis can occur. Adults are at higher risk of more serious disease and complications. Reactivation of the virus in nerve endings in later life can result in Herpes zoster infection, commonly known as Shingles.
Where is it found?
Chickenpox is endemic in all countries.
Risk to travellers
For travellers, the risk of chickenpox could be as high in developed countries as in developing ones. Few countries routinely use the vaccine, but coverage is increasing. Non-immune adults and children should consider vaccination, especially those planning extended stays or extensive travel.
Varicella-containing vaccine is recommended for:
- children aged 12 months to <14 years
- adolescents aged ≥14 years and adults who have not received 2 doses of varicella-containing vaccine, particularly
- healthcare workers
- childhood educators and carers
- people who work in long-term care facilities
What is Varicella (Chickenpox) Vaccination?
Live, attenuated virus vaccine. (Should not be given to persons who are immune compromised, to pregnant women or those planning pregnancy. Pregnancy should be avoided for 28 days after vaccination.)
Contraindications: Should not be administered to individuals who have previously experienced a serious reaction to this vaccine, who are known to be hypersensitive to any of the vaccine components or who are unable to receive a live vaccine (see above).
One dose for children under 14 years, routinely given at 18 months of age in combination with measles mumps and rubella antigens as part of the national immunisation schedule.
A second dose is recommended to prevent break-through infections; however it is not part of the national immunisation schedule
2 doses given at least 4 weeks apart for individuals over ≥14 years and adults
Level of protection
Vaccine efficacy is estimated to be 90% against infection and 95% against severe infection.
Possible Side Effects
Pain and swelling at site of infection in 7 to 30% of persons.
Mild, chickenpox-like rash in 5% of recipients (usually fewer than 5 lesions) lasting less than 1 week.
Fever in 10-15% of healthy children and adults.
As with all vaccines, there is a small risk of allergic reactions