Article What Arguments against COVID-19 Vaccines Run on Facebook in Poland: Content Analysis of Comments Dominik Wawrzuta * , Mariusz Jaworski , Joanna Gotlib and Mariusz Panczyk   Citation: Wawrzuta, D.; Jaworski, M.; Gotlib, J.; Panczyk, M. What Arguments against COVID-19 Vaccines Run on Facebook in Poland: Content Analysis of Comments. Vaccines 2021, 9, 481. https://doi. org/10.3390/vaccines9050481 Academic Editor: Barbara Rath Received: 21 April 2021 Accepted: 6 May 2021 Published: 10 May 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). Department of Education and Research in Health Sciences, Medical University of Warsaw, 02-091 Warsaw, Poland; mariusz.jaworski@wum.edu.pl (M.J.); joanna.gotlib@wum.edu.pl (J.G.); mariusz.panczyk@wum.edu.pl (M.P.) * Correspondence: dominik@wawrzuta.pl Abstract: Social media allow anti-vaxxers to quickly spread misinformation and false statements. This situation may lead to an increase in vaccine hesitancy. We wanted to characterize what arguments against COVID-19 vaccines run on Facebook in Poland. We analyzed Facebook comments related to the five events of the introduction of COVID-19 vaccines—announcements of the efficacy of the Pfizer- BioNTech (09.11.2020), Moderna (16.11.2020), and AstraZeneca (23.11.2020) vaccines, registration of the Pfizer-BioNTech vaccine by the European Medicines Agency (21.12.2020), and the first vaccination in Poland (27.12.2020). We collected the comments from fanpages of the biggest Polish media and then established their main anti-vaccine themes. We found that the negative arguments about COVID-19 vaccines can be divided into 12 categories. Seven of them are universal and also apply to other vaccines but five are new and COVID-19’ specific. The frequency of arguments from a given category varied over time. We also noticed that, while the comments were mostly negative, the reactions were positive. Created codebook of anti-vaccine COVID-19 arguments can be used to monitor the attitude of society towards COVID-19 vaccines. Real-time monitoring of social media is important because the popularity of certain arguments on Facebook changes rapidly over time. Keywords: Facebook; vaccine hesitancy; vaccine; COVID-19; infodemiology 1. Introduction 1.1. Background Social media provide great opportunities for sharing convictions and opinions. Unfortunately, there is also a place for conspiracy theories. Almost half of the health content published on social media contains misinformation [1]. The subject of vaccinations and infectious diseases is, next to oncological topics, the most frequently misrepresented in social media [2]. For these reasons, social media are currently regarded as the main communication tool for people with anti-vaccine attitudes [3,4]. An example of an uncontrolled spread of misinformation on vaccination on social media is the measles outbreak in Samoa. In July 2018, two Samoan children died after MMR vaccination because nurses inadvertently used curare instead of water to dilute the MMR vaccine. This resulted in an increased activity of local anti-vaxxers on Facebook, who took action to discourage vaccination [5]. As a result, measles vaccination coverage in Samoa decreased to 31% [6]. Consequently, measles outbreak occurred on the islands in September 2019, causing over 5000 cases and 83 deaths in a country with the population of 200,000 [7]. Finally, the authorities decided to organize a vaccination campaign and arrest some anti- vaccination campaigners spreading misinformation on Facebook [8]. When 95% of eligible people in Samoa got vaccinated, the outbreak was eliminated [9]. Another case happened during the COVID-19 pandemic when European trust in AstraZeneca’s vaccine plummeted after spreading information on rare episodes of blood clotting after the vaccination [10]. This decline in confidence has occurred in spite of the European Medicines Agency’s Vaccines 2021, 9, 481. https://doi.org/10.3390/vaccines9050481 https://www.mdpi.com/journal/vaccines