Parental acceptance and knowledge of varicella vaccination in relation to socioeconomics in Sweden: A cross-sectional study.

Varicella infection is a highly contagious disease which, whilst mild in most cases, can cause severe complications. Varicella vaccination is available privately in Sweden and is currently being reviewed for inclusion in the Swedish Public Health Agency's national immunisation program (NIP). A cross-sectional study of parents of Swedish children aged 1-8 years (n = 2212) was conducted to understand parental acceptance, beliefs and knowledge around varicella infection and vaccination. Respondents generally viewed varicella infection as a mild disease, with only a small proportion aware of potential severe complications. While 65% of respondents were aware of the vaccine, only 15% had started the course of vaccination as of February 2019. Further, 43% of parents did not intend to vaccinate, most commonly due to lack of inclusion in the NIP, but also due to perception of mild disease. Nevertheless, if offered within the NIP, 85% of parents would be highly likely to vaccinate their child. A number of statistically significant differences in awareness and behaviours were observed between sociodemographic subgroups. In general, women were more aware of vaccination (72%) compared to men (58%). Among unemployed or respondents with elementary school education, awareness was below 43%, and among respondents with high income the awareness was above 75%. Similarly, among unemployed or respondents with a low income the vaccination rate was as low as 30% compared with at least 57% among respondents with a high income. Respondents from metropolitan areas, those with university degrees and respondents with a higher income were more likely to be aware of the varicella vaccine and to have vaccinated their child. Whilst inclusion in the NIP is clearly the main driver for uptake, these identified knowledge gaps should inform educational efforts to ensure that all parents are informed of the availability and benefits of the varicella vaccine independent of socioeconomic status.
Competing Interests: This work was funded by Merck Sharp & Dohme Corp. (MSD), a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA, which manufactures vaccines for varicella (Varivax and ProQuad). Lisen Arnheim-Dahlström owns Lisen Arnheim-Dahlström Consulting and has received consulting fees from MSD Sweden. Natalie Zarabi is an employee of MSD Sweden, and owns stock in Merck & Co., Inc., Kenilworth, NJ, USA. Karin Hagen is an employee of MSD Sweden, currently appointed for Organon, and owns stock in Merck & Co., Inc., Kenilworth, NJ, USA. Goran Bencina is an employee of MSD Spain, and owns stock in Merck & Co., Inc., Kenilworth, NJ, USA. Employees of the funders participated in the study design, in the analysis and interpretation of the data, in the preparation of the manuscript, and in the decision to submit the manuscript for publication. This does not alter our adherence to PLOS ONE policies on sharing data and materials.