A major outbreak of measles looks likely to have been avoided after a student with the virus attended an Auckland high school while infectious.

There have been no new cases identified and only about 55 of the 1000 Albany Senior High School staff and students remain in quarantine.

“It’s looking like we’re beginning to start breathing and ... I think we have dodged a bullet on this one so far,” Dr Nikki Turner, medical director of The Immunisation Advisory Centre, said.

“We’re not out of the woods yet but it’s looking promising.”

She said the incubation period was usually seven to 10 days but could be up to 14 days.

“It’s getting less and less likely as time goes on. This is just following through a standard public health pathway.”

University of Auckland Immunisation Advisory Centre medical director Dr Nikki Turner says it looks likely we've avoided a measles outbreak. Photo / Supplied

Albany Senior High School was shut down by Auckland Regional Public Health on Thursday last week after it was discovered a student with measles had been at school, while infectious, for two days the previous week.

The infected student had been in all five of the school’s open-plan modern-learning environments, mixing with several year levels and classes. It meant all 900 students and 100 staff were considered close contacts and were asked to isolate until their vaccination status could be confirmed.

It was confirmed a household member of the student, who had been overseas recently, also had measles.

Auckland Regional Public Health Service medical officer of health Dr Julia Peters said there had been no new cases identified yet and only about 55 staff and students were still in quarantine at home.

That was because those people could not provide sufficient evidence of immunity to measles.

A small number were still waiting on the results of blood tests to determine their immune status, so the number in quarantine could still decrease, she said.

The rest were due to be released from quarantine over the weekend, pending a final symptom check.

People are considered immune to measles if they were born before January 1, 1969, have evidence of having two doses of the measles, mumps and rubella (MMR) vaccine after the age of 12 months, have had measles before, or if a blood test confirms they are immune.

Peters said the school decided it was able to resume face-to-face learning on Tuesday after sufficient numbers of staff were released from quarantine.

Claire Amos, principal of Albany Senior School. Photo / Dean Purcell

Albany Senior High School principal Claire Amos said, in a message to parents on Monday, that the teachers who still needed to isolate would continue to teach from home for the week, with another teacher in class to support students.

The school would also ensure students still isolating could continue to learn from home.

Peters thanked the school community for its help and co-operation over the past week.

Te Whatu Ora was also working with the school to arrange an on-site vaccination clinic in the next few weeks, she said.

Turner said the case was a reminder of how effective the vaccine was and served as a “thank you” to those who were vaccinated because it kept the community safe.

“It is a reflection that, of the people around the people who had measles, the majority of them would have been immune and that’s what stops it spreading.

“Congratulations New Zealand. We want our vaccination rates up higher but the fact that a lot of people are vaccinated has made a big difference here in that measles hasn’t spread.”

The MMR vaccine is free for everyone under 18 and for all adults born after January 1, 1969, who are eligible for free healthcare in New Zealand.