Overview
In New Zealand, chickenpox is a common illness in childhood and most adults will have had the disease as a child. Adults who grew up in tropical countries are less likely to have had chickenpox in childhood. Adolescents and adults are at higher risk than children of severe disease and complications.
Varilrix is a live vaccine containing a weakened form of the varicella-zoster virus to protect children and adults from chickenpox.
Varilrix is funded from 9 months of age for special groups and as part of the National Schedule from 15 months and as a catchup from 11 years of age.
In children aged from 9 months to under 13 years, a single dose of vaccine will protect around eight in 10 children. Up to two in 10 may still get chickenpox but are usually protected against moderate to severe disease. Children aged 13 years and older, and adults up to 50 years who are not immune, require two doses of the vaccine for protection against moderate to severe disease. The vaccine may also prevent or reduce the severity of chickenpox in someone who has not previously had chickenpox or been vaccinated, if it is given within 3–5 days of exposure to the disease.
In extremely rare cases, a vaccine recipient with a vaccine-related rash could transfer the vaccine virus to another person. With more than 60 million vaccine doses given, 10 cases have been documented. There is no risk of the vaccine virus being transferred to another person if there is no vaccine-related rash. Vaccine recipients who develop a rash should avoid contact with people who are pregnant and not immune to chickenpox, newborn babies and people known to have weakened immune systems until the rash has gone.
Funded Varilrix is available from ProPharma.
Varilrix for non-funded child and adult doses is available from Healthcare Logistics.
Note: From 1 July 2024, there was a brand change on the National Schedule from Varivax to Varilrix.
Responses to vaccine
- Headache and/or tiredness
- Mild rash 5–26 days after immunisation
- High fever
- Transfer of vaccine virus from a vaccine rash to another person
Other formulations and brands
Other brands of varicella vaccine: Varivax
Schedule and administration
The National Immunisation Schedule varicella vaccine brand is Varilrix for eligible children and adults aged 12 months or older.
- Children born on/after 1 April 2016 can have one free varicella vaccine dose when they turn 15 months. This includes those who have previously had one purchased chickenpox vaccine dose or had a chicken pox infection.
- Those born from 1 July 2006 can have one free varicella vaccine dose when they turn 11 years IF they have not already had a chickenpox immunisation or had chickenpox infection. (These children will have turned 11 on or after 1 July 2017). Two doses are recommended from 13 years, the second dose would be unfunded.
- Those born before 1 July 2006 and adults do not get a free varicella vaccine dose unless they have a medical condition that meets the eligibility criteria for one of the ‘special groups’ described in the Pharmaceutical Schedule.
Varilrix will continue to be the funded varicella vaccine brand for infants aged 9–11 months who meet one of the special groups' eligibility criteria.
Special groups
One dose of Varilrix for infants aged 9–11 months followed by one dose of Varilrix from 12 months of age who meet one of the eligibility criteria below:
- HIV-positive with mild or moderate immunosuppression, on the advice of their specialist
- Prior to elective immunosuppressive therapy that will be longer than 28 days
- With chronic liver disease who may in future be candidates for transplantation
- With deteriorating renal function before transplantation
- Prior to solid organ transplantation
- After a haematopoietic stem cell transplantation, on the advice of their specialist
- After chemotherapy, on the advice of their specialist
- With an inborn error of metabolism at risk of major metabolic decompensation
- Household contact of a child or adult patient who is immunocompromised or undergoing a procedure leading to immunocompromise, where the household contact has no clinical history of varicella infection or immunisation
Varicella vaccine for purchase
Should children and adults have one or two varicella vaccinations?
Children aged less than 13 years
- Parents may choose to purchase a second dose of varicella vaccine, which is recommended to be administered a minimum of six weeks after the first dose. If a shorter gap is required then a minimum of four weeks can be considered.
- Infants who receive their first varicella vaccine dose when aged under 12 months of age are recommended to have a second varicella vaccination from age 12 months. Maternal antibodies against chickenpox could be present in infants aged under 12 months and affect the infant's individual response to the vaccination.
- In all children aged under 13 years, one dose gives good protection, two doses give optimal protection.
Children aged 13 years or older and adults
- The standard varicella vaccine schedule is two doses administered six weeks apart for individuals in this age group receiving varicella vaccine for the first time. A minimum of four weeks can be considered if a shorter gap is required.
- Varicella vaccination is not routinely recommended for adults aged 50 years or older.
Catch-up doses
- All children and adults up to 50 years of age, as required.
- Varicella vaccination is not routinely recommended for adults aged 50 years or older.
Vaccine storage and preparation
Store vaccine and diluent as per cold chain between 2°C to 8°C.
Administration
- The Ministry of Health recommends that varicella vaccine is administered via the IM route. However, administration of varicella vaccine by either the IM or SC injection route delivers a valid dose of vaccine. In the original clinical trials, varicella vaccine was given by SC injection and this became the recommended route of injection. Since then, data has shown that administration of varicella vaccine by IM injection generates an immune response equal to the response when the vaccine is given via the SC route, and the vaccine is also well-tolerated.
For infants likely to require a liver or kidney transplantation who are on an accelerated vaccination schedule (refer to table 4.4 in the current Immunisation Handbook)
- Varilrix can be administered concurrently with other Schedule vaccines, including MMR or hepatitis A. Separate syringes and different injection sites should be used.
- If Varilrix is not given at the same visit as another live injectable vaccine e.g. MMR, a four-week interval between the two live virus vaccines should be observed.
Vaccine Safety
Varicella vaccine can be given to:
- A person living with a newborn baby or a pregnant woman or a person who is immune suppressed.
Immunisation should be postponed in individuals suffering from a fever over 38°C. However, the presence of a minor infection is not a reason to delay immunisation.
Varicella vaccine should not be given to:
- Anyone who has a severe weakness of the immune system, see chapter 22.6.1 in the Immunisation Handbook.
- Anyone who had a severe allergic response (anaphylaxis) to a previous dose of this vaccine or a component of this vaccine.
- Women who are currently pregnant. Women are advised to delay pregnancy for four weeks after receipt of a varicella vaccine dose.
- People who have received another live injected vaccine within the previous four weeks
Advice should be sought for the following groups:
- People known to have a weakened immune system.
- People receiving high-dose steroid medicine, e.g. prednisone, for more than 14 days. They should wait for at least four weeks after their treatment has finished before receiving the vaccine.
- People taking antiviral medication, e.g. tablets for cold sores. These should be stopped for 24 hours prior to immunisation and not restarted for 14 days afterwards.
- Children taking aspirin. Whilst there has been no association between chickenpox immunisation and Reye’s Syndrome, avoidance of aspirin around the time of immunisation and for six weeks afterward is advised as a precaution.
- People who have received a blood product in the 11 months before immunisation.
- People expecting to receive a blood product in the two months after immunisation. These should not be given for two months after immunisation unless their use outweighs the benefits of the immunisation.
It is possible but extremely rare for a person with a vaccine-related rash to transfer the vaccine virus to another person. Only 10 cases have been reported from around 60 million vaccine doses in the U.S. There is no risk of the vaccine virus being transferred to another person if there is no vaccine-related rash.
Vaccine Effectiveness
For optimal protection (99%) against all chickenpox disease in children aged nine months up to and including 12 years of age a vaccine course of two doses of Varilrix separated by at least six weeks is recommended. However, a single dose of vaccine offered from the age of 12 months can provide 70–90% protection against all chickenpox, and more than 95% will be protected from moderate-severe disease but may still get mild chickenpox (often fewer than 50 lesions).
Available information suggests that chickenpox vaccinations may decrease the risk of developing shingles later in life compared with having the wild-type disease.
References
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