A third dose of the measles, mumps and rubella (MMR) vaccine is needed to protect young adults from the mumps outbreak, an Otago University researcher says.
New Zealand is in the grip of an outbreak that began in Auckland early last year and there have been more than 1000 cases.
Infectious diseases physician Dr Ayesha Verrall says urgent proactive action is needed.
"Young adults in high risk settings can benefit from a third dose of the measles, mumps and rubella vaccine, even if they completed their two doses as a child," she said.
"The vaccine is about 90 per cent effective against mumps, but its protection reduces over time so young adults who received two doses might have lost their protection from the vaccine."
Dr Verrall said previously vaccinated people needed to know they might also be susceptible. Failing to communicate this risked undermining public confidence in vaccines.
She said the Ministry of Health needed to fund and offer a third dose to people aged 10 to 29, even if they had received two doses already.