Citation: Jamison, A.M.; Rimal, R.N.; Ganjoo, R.; Burleson, J.; Alperstein, N.; Bhaktaram, A.; Pascual-Ferra, P.; Mohanty, S.; Parida, M.; Rath, S.; et al. Promoting Vaccination in India through Videos: The Role of Humor, Collectivistic Appeal and Gender. Vaccines 2022, 10, 1110. https:// doi.org/10.3390/vaccines10071110 Academic Editors: Paola Frati and Giuseppe La Torre Received: 20 May 2022 Accepted: 5 July 2022 Published: 12 July 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 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/). Article Promoting Vaccination in India through Videos: The Role of Humor, Collectivistic Appeal and Gender Amelia M. Jamison 1, * , Rajiv N. Rimal 1 , Rohini Ganjoo 2 , Julia Burleson 1 , Neil Alperstein 3 , Ananya Bhaktaram 1 , Paola Pascual-Ferra 3 , Satyanarayan Mohanty 4 , Manoj Parida 4 , Sidharth Rath 5 , Eleanor Kluegel 3 , Peter Z. Orton 6 and Daniel J. Barnett 1,7 1 Department of Health, Behavior and Society, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA; rimal@jhu.edu (R.N.R.); jburles4@jhu.edu (J.B.); abhakta2@jhu.edu (A.B.); dbarnet4@jhu.edu (D.J.B.) 2 Department of Biomedical Laboratory Sciences, George Washington University, Ashburn, VA 20147, USA; rganjoo@egwu.edu 3 Department of Communication, Loyola University of Maryland, Baltimore, MD 21210, USA; nalperstein@loyola.edu (N.A.); ppascualferra@loyola.edu (P.P.-F.); emkluegel@loyola.edu (E.K.) 4 Satya Nagar, Bhubaneswar 751007, Odisha, India; satya.dcor@gmail.com (S.M.); manoj.dcor@gmail.com (M.P.) 5 Swasthya Plus Network, Chandrasekharpur, Bhubaneswar 751017, Odisha, India; sidharth@odicast.com 6 Wellflix Inc., Hillsborough, NC 27278, USA; orton@wellflix.net 7 Department of Environmental Health & Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA * Correspondence: ajamiso5@jhmi.edu Abstract: Vaccination hesitancy is a barrier to India’s efforts to control the COVID-19 pandemic. Considerable resources have been spent to promote COVID-19 vaccination, but evaluations of such efforts are sparse. Our objective was to determine how vaccine videos that manipulate message appeal (collectivistic versus individualistic), tone (humorous versus serious), and source (male versus female protagonist) toward vaccines and vaccination. We developed eight videos that manipulated the type of appeal (collectivistic or individualistic), tone of the message (humor or serious), and gender of the vaccine promoter (male or female) in a 2 × 2 × 2 between-subjects experiment. Participants (N = 2349) were randomly assigned to watch one of eight videos in an online experiment. Beliefs about vaccines and those about vaccination were obtained before and after viewing the video. Manipulation checks demonstrated that each of the three independent variables was manipulated successfully. After exposure to the video, beliefs about vaccines became more negative, while beliefs about vaccination became more positive. Humor reduced negative beliefs about vaccines. Collectivism and protagonist gender did not affect beliefs about vaccines or vaccination. Those able to remember the protagonist’s gender (a measure of attention) were likely to develop favorable beliefs if they had also seen the humorous videos. These findings suggest that people distinguish beliefs about vaccines, which deteriorated after exposure to the videos, from beliefs about vaccination, which improved. We recommend using humor when appropriate and focusing on the outcomes of vaccination, rather than on the vaccines themselves. Keywords: vaccine hesitancy; vaccine confidence; collectivism; humor; message testing 1. Introduction India has borne a significant burden of the COVID-19 pandemic. By June 2022, India had reported more than 43 million cases, with an overall prevalence of 3.2% [1]. India’s mass vaccination campaign against COVID-19 was initially plagued by vaccine shortages and unexpected delays, but by April 2022, approximately 73% of the population had received their first dose, with 62% receiving both the first and second doses of the vaccine [2]. The Indian government provided the first two doses to the population for free. At the time Vaccines 2022, 10, 1110. https://doi.org/10.3390/vaccines10071110 https://www.mdpi.com/journal/vaccines