They found that 144 children were admitted to a hospital with chickenpox in the two years to November 2013. Their median age was 2.4 years and Maori and Pacific Island children were around three times more likely than European children to be admitted to hospital with the illness.
Of those admitted, 75 per cent had an infection, 11 per cent had a respiratory disorder and 11 per cent had neurological symptoms.
"Cases that require ICU admission are more likely to have ongoing problems upon discharge, as shown in our review where almost one-third [of] cases have permanent disability," the researchers say in the Journal of Paediatrics and Child Health.
"There were no reported deaths; however, 19 per cent had ongoing problems at discharge."
They say their study "gives support for the inclusion of universal varicella vaccine".
"Cost-effectiveness modelling of a funded universal varicella vaccination programme -- single dose -- in New Zealand suggested a return of $2.79 for every dollar spent on the programme."
Auckland GP Dr John Cameron said many considered chickenpox a normal part of growing up.
"Parents think, 'We all had it, so the kids will have it as well'."
"It's now a preventable disease and people need to be aware of the dangers associated with chickenpox infection."
"It makes kids utterly miserable and it can lead to hospitalisation, as this research shows."
Having the jab at his Westmere clinic costs $75.
Waikato immunisation facilitator Helen Ride said the illness could impose a financial burden on families.
"Even in a mild case, the child will be excluded from day-care or school and will require a parent to stay home and care for the child. If a number of children in the household are susceptible to chickenpox then this can equate to over four weeks home caring for infected children."
The Immunisation Advisory Centre at Auckland University has been calling for the Government to fund a chickenpox vaccine for at least a decade.
Common side-effects of chickenpox vaccine are listed as including soreness at the injection site. Uncommon side-effects include shingles later in life, and rare/very rare side-effects include severe allergic reaction.