The National Immunisation Schedule varicella vaccine brand is changing from Varilrix to Varivax 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, including those who have previously had one purchased chickenpox vaccine dose.
• Children born 1 July 2006 to 31 March 2016 can have one free varicella vaccine dose when they turn 11 years IF they have not already had a chickenpox immunisation or had chickenpox disease.
• Children 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.

Special groups

Two doses of Varilrix are funded for children from 12 months of age and adults who have not previously had chickenpox or two varicella vaccination, and meet at least one of the following criteria:

• Who are 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
• Who are a 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

Infants who received one Varilrix vaccine dose aged 9–11 months because they met one of the special groups eligibility criteria receive one Varivax dose from 12 months of age to complete a funded two-dose course of varicella vaccines.

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 have 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.
• Varivax and the alternative Varilrix vaccine are interchangeable within a two dose course of vaccines.
• Varivax can be administered concurrently with other Schedule vaccines, including MMR, Hib and PCV10 or PCV13. Separate syringes and different injection sites should be used.
• If Varivax is not given at the same visit as another live injectable vaccine e.g. MMR, a 4 week interval between the two live virus vaccines should be observed.

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 can be administered a minimum of 4 weeks before or after the first dose.
• 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 a minimum of 4 weeks apart for individuals in this age group receiving varicella vaccine for the first time.

Special groups aged 9 months or older

• Two vaccine doses are recommended and funded for infants, children and adults who meet the eligibility criteria for one of the ‘special groups’ described in the Pharmaceutical Schedule.

Catch-up doses

All eligible children, and adults up to 50 years of age, as required.

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
• 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 4 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.

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 Varivax separated by at least four 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.

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