Measles and the 'Immunity Gap'

This year, more than 50 people in New Zealand have been hospitalised with measles. And 2019 isn't a mere blip - it's the fourth such outbreak in a single decade. Blame is often apportioned to hardline anti-vaxxers, but researchers say an "immunity gap" is in fact allowing the disease to flourish. RNZ's Kate Newton has been looking into the issue.