One in four New Zealanders has been born overseas and new migrants are ahead of other Kiwis when it comes to vaccinating their babies.

Migrant families are more likely than other New Zealanders to vaccinate their babies on time, according to new University of Auckland research.

The study found children of recent migrants, defined as moving to New Zealand within the previous five years, were more likely than non-migrants to receive vaccines at six weeks, three months and five months.

“We found that the children born to two born-overseas parents had the highest timely vaccination rate, followed by those who had one parents born overseas and then at the lowest rate were children who had two New Zealand-born parents,” says lead researcher Dr Ladan Hashemi, a senior research fellow at Waipapa Taumata Rau, the University of Auckland.

The researchers looked at immunisation records for more than 6,800 babies of a representative sample of the same number of women who were expected to give birth between April 2009 and March 2010 and 4,400 of their partners, all with consent.

They used data from the Growing Up in New Zealand study as well as immunisation data.

Timeliness was defined as within 30 days of the scheduled date for vaccination.

This new study found migrant families were poorer than non-migrants, but they still had higher rates of timely childhood vaccinations. Timeliness is important for preventing spread of vaccine-preventable illnesses, such as measles.

These advantages diminished for migrants who had been living in the country longer.

“This is the opposite to what you would expect. As you stay longer in the country, life is going to be easier, your income is going to be better, but they found the drop-off in timely vaccination,” say Dr Hashemi.

This could be because of anti-vaccination attitudes being a public health issue in New Zealand, Dr Hashemi says.

“For the first five years of living in New Zealand, migrants are not quite integrated into mainstream culture.

“But, as time goes on, they are more likely to acquire the English language, and be exposed to media and social media that is full of anti-vaccine information, as well as meeting people who are anti-vaccines. So, over time, those vaccination rates go down.”

Another factor is the ‘migration paradox’, Hashemi says.

This is where migrants are moving to a new country because they are seeking better opportunities for themselves and their children, including having better health.

“Research from the US shows that migrant mothers are very determined to provide the best health for their children,” says Dr Hashemi.

In New Zealand, 25 per cent of the population has been born overseas, a percentage that has been increasing over time.

Migrants are generally more educated than other New Zealanders, including ten percent more likely to have a university education.

This is likely to be due to the points system, where migrants need to be highly educated and also healthy, including having good health behaviours.

Another recent study from the University of Auckland and led by Hashemi found children of migrant children were less likely to be obese than non-migrants and less likely to have an obesogenic lifestyle. See Advances in Public Health.

One recommendation from the new study was a need for qualitative research to find out why vaccination drops off the longer migrants live in New Zealand. 

In the same paper, the authors conclude migrant families’ experiences could inform vaccine promotion and policies to increase vaccination uptake.

Vaccine is the pre-eminent journal in the field of vaccinology. It is the official journal of The Japanese Society for Vaccinology and is published by Elsevier. Click here: https://www.sciencedirect.com/journal/vaccine