by City University London

Credit: CC0 Public Domain

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

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

Dr. Ladan Hashemi was the lead researcher on the study. She is a Senior Research Fellow at City and an Honorary Senior Research Fellow at Waipapa Taumata Rau, the University of Auckland. She said, "We found that children had the highest rates of timely vaccination when both parents were born overseas. This rate went down for children who had one parent that was born overseas and dropped even further for children with two New Zealand-born parents."

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

Timeliness is important for preventing the spread of vaccine-preventable illnesses, such as measles. The researchers looked at immunization 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 immunization data.

This new study found migrant families were poorer than non-migrants, but they still had higher rates of timely childhood vaccinations.

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 behaviors.

Educated parents are more likely to vaccinate their children. Another factor is the 'migration paradox', Dr. 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," Dr. Hashemi says.

These advantages diminished for migrants who had been living in the country longer. "This is the opposite of 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," Dr. Hashemi adds.

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 are full of anti-vaccine information, as well as meeting people who are anti-vaccines. So, over time, those vaccination rates go down."

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

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

Another recent study led by Dr. Hashemi, which was published in Advances in Public Health, found children of migrant children were less likely to be obese than non-migrants and less likely to have an obesogenic lifestyle.

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

The paper, titled 'Migration and infant immunization timeliness in New Zealand: Evidence from the Growing Up in New Zealand study' was published in Vaccine.

More information: Mehdi Rahimi et al, Childhood Overweight/Obesity amidst Migration, Socioeconomic Factors, and Obesogenic Behaviors: Insights from the Growing Up in New Zealand Study, Advances in Public Health (2023). DOI: 10.1155/2023/5592593

Ladan Hashemi et al, Migration and infant immunization timeliness in New Zealand: Evidence from the Growing Up in New Zealand study, Vaccine (2024). DOI: 10.1016/j.vaccine.2024.02.053

Journal information: Public Health  , Vaccine 

Provided by City University London