# The importance of parental human papillomavirus vaccine series initiation for reducing sex disparities in human papillomavirus vaccine series initiation among children in the United States

## TL;DR

Boys are less likely to start the HPV vaccine series, but this gap disappears if their parents have started the vaccine, suggesting parental influence is key.

## Contribution

This study is the first to show that parental HPV vaccination status modifies sex disparities in children's vaccine initiation.

## Key findings

- Male children had lower odds of initiating the HPV vaccine series overall.
- Children with vaccinated parents had higher odds of initiating the HPV vaccine series.
- The sex disparity in vaccine initiation among male children was only present when parents were unvaccinated.

## Abstract

Male children are less likely to initiate the human papillomavirus (HPV) vaccine series than their female counterparts. Furthermore, evidence suggests children with parents who initiated the vaccine series may be more likely to do the same. However, no studies have examined if parents' vaccination status modifies sex differences in HPV vaccine series initiation among children.

Using the 2022 National Health Interview Survey data, we examined the association between parents' HPV vaccination status (unvaccinated, initiated the vaccine series, unknown) and sex disparities in HPV vaccine series initiation among children using weighted multivariable logistic regression models.

Among 2200 parent-child dyads, less than half of parents (15.6 %) and children (32.6 %) initiated the HPV vaccine series. In adjusted analysis, male children had decreased odds of vaccine series initiation (OR: 0.73, 95 % CI: 0.58, 0.92). Children with parents who initiated the vaccine series had an increased odds of initiating the vaccine series compared to those whose parents were unvaccinated (OR: 2.88, 95 % CI: 2.00, 4.15). When stratified by parent's HPV vaccine series initiation, male children only had a decreased odds of HPV vaccine series initiation among children with unvaccinated parents (OR: 0.69, 95 % CI: 0.54, 0.89).

Male children were only less likely to initiate the HPV vaccine series among children whose parents were unvaccinated against HPV. Thus, healthcare providers should engage both the parent and child in the vaccine recommendation process. Doing so may improve HPV vaccine series initiation for parents who are within the recommended age range and male children.

•Male children were less likely to have initiated the human papillomavirus vaccine (HPV) series overall.•Children whose parents initiated the HPV vaccine series were more likely to initiate the vaccine series.•Male children were only less likely to initiate the HPV vaccine series among children whose parents were unvaccinated.

Male children were less likely to have initiated the human papillomavirus vaccine (HPV) series overall.

Children whose parents initiated the HPV vaccine series were more likely to initiate the vaccine series.

Male children were only less likely to initiate the HPV vaccine series among children whose parents were unvaccinated.