You do not need any vaccinations prior to visiting New Zealand, although you should take care to avoid insect bites during summer months.
There is no reciprocal heath care provision agreement between the UK and New Zealand, so you should always ensure that you have adequate, comprehensive heath and travel insurance to provide for you in the event of sickness. Repatriation back to the UK from New Zealand is very expensive, and you should also ensure that your travel insurance covers you for any activities you may undertake in the region.
