New Zealand's latest measles case could have nightmare consequences from a medical perspective, a leading paediatrician says.

Dr Owen Sinclair is among many medical experts with grave concerns for vulnerable groups if there is a measles outbreak in Auckland.

Health alerts have been issued after a new measles case was confirmed yesterday, with people in Auckland asked to check if they could have been exposed.

Health New Zealand said the case was linked to overseas travel in Asia, and the person with measles had been at Woolworths Kelston, on Fullers360 ferries, and at an Auckland carpark during the time they could be infectious.

More locations of interest - including a second supermarket and a West Auckland pharmacy - were confirmed late this afternoon.

"The last time we had sort of an outbreak in Auckland, it was attributed to two deaths in New Zealand, and then the measles that occurred here moved to Samoa and 83 people died over there.

"We really thought we'd got rid of it, but now it's come back due to a number of reasons," said Dr Sinclair.

Dr Sinclair said low rates of vaccination were often caused by difficulty in accessing immunisation healthcare.

New Zealand's overall vaccination rates against measles is at about 80 percent, according to Health NZ.

Earlier this month, Health Minister Simeon Brown said the government was targeting 95 percent of children being fully vaccinated by 24 months.

Dr Sinclair said at 95 percent coverage, New Zealand would effectively have herd immunity.