Changes in Attitudes towards the COVID-19 Vaccine and the Willingness to Get Vaccinated among Adults in Poland: Analysis of Serial, Cross-Sectional, Representative Surveys, January–April 2021

Abstract
In December 2020, the first coronavirus disease 2019 (COVID-19) vaccine was authorized in the European Union. This study aimed to assess the changes in attitudes towards the COVID-19 vaccine and the willingness to get vaccinated among adults in Poland between January and April 2021. Secondary data analysis was carried out using data obtained from nationally representative cross-sectional surveys (four consecutive waves: January 2021, n = 1150; February 2021, n = 1179; March 2021, n = 1154; April 2021, n = 1131) carried out by the Public Opinion Research Center. About 31.3% of individuals declared a lack of willingness to vaccinate against COVID-19 regardless of the study wave. Significant changes (p < 0.001) were observed by gender and age. The highest percentage of respondents who declared a lack of willingness to vaccinate against COVID-19 was observed in the youngest age group (18–34 years), 48.5% among males and 45.6% among females. Among individuals over 65 years of age, males significantly more often declared their willingness to be vaccinated than females (p < 0.001). The main argument against the COVID-19 vaccine was concern about the potential side effects. Differences in attitudes towards the COVID-19 vaccine in respect of gender and age indicate the need to implement personalized communications to encourage different social groups to vaccinate against COVID-19.