Understanding parental vaccine acceptance of childhood vaccinations in Sweden

The vaccination coverage in Sweden's National Immunization Program (NIP) has been high
and stable for decades. Although the coverage is high, few studies have assessed parental vaccine
acceptance in Sweden. This doctoral thesis aimed to provide an in-depth understanding of current
parental vaccine acceptance, focusing particularly on Human papillomavirus (HPV) and measles, mumps and rubella (MMR) vaccinations to further identify factors influencing low vaccine acceptance and to evaluate a tailored intervention to improve vaccine uptake. The purpose of the studies was to develop evidence-based methods to systematically inform the management and implementation of the NIP in Sweden regarding parental vaccine acceptance. Mixed methods were used to assess parental vaccine acceptance, including a survey and focus group discussions. A retrospective registry-based study, which included nearly 500,000 girls born from 2002 to 2010, examined factors for non-timely HPV vaccination and their respective parents. MMR vaccination was in focus for designing and implementing a tailored intervention based on the Tailoring
Immunization Programs (TIP) approach targeting nurses working in an area with low MMR uptake. To evaluate, in-depth interviews were conducted with the nurses. The findings of the studies identified driving factors and barriers to parental vaccine acceptance. The majority of parents (79%) vaccinated their child without any doubts while others (19%) vaccinated their child but had questions or concerns and a small group declined at least one vaccination for their child (2%).
Parents had confidence in vaccinations as they perceived them as safe and effective and trusted the
system and nurses implementing the NIP. Individual and societal factors were driving factors as children were vaccinated for solidarity reasons and not only to get individual protection. Challenges and barriers identified related to safety concerns of adverse events or perceptions of negative or inadequate information. Nurses had a key role in the high parental vaccine acceptance. They provided a backbone for the NIP. The TIP approach provided a valuable, stepwise process that facilitated the identification and design of a tailored intervention targeting nurses. According to the nurses, the dialogue with parents having low MMR vaccine acceptance, was facilitated and enhanced following the tailored intervention. The TIP approach can be useful in addressing vaccination barriers and tailoring NIP to support an equitable and resilient program. Not being HPV vaccinated, according to the NIP in grades 5 and 6, was associated with parents having low or medium income or high school education as their highest education. Girls to parents where one was born abroad and the other in Sweden were also associated with not being vaccinated, regardless of whether the girl was born in Sweden or abroad. To conclude, the driving factors and barriers identified in the studies of this thesis provide an in-depth understanding of the current parental of vaccine acceptance. The driving factors can be promoted, and barriers can be
addressed to strengthen the NIP. Systematic assessment of parental vaccine acceptance and inequity is valuable to inform the NIP implementation and to maintain high vaccination coverage in the future.