To evaluate whether the social media strategy developed for the campaign Stop HPV - stop cervical cancer was successful at engaging target groups in communication regarding HPV vaccination. In 2009, the Human Papillomavirus (HPV) vaccine became part of the Danish childhood vaccination program to protect Danish girls from cervical cancer. In 2015, after a period of massive media coverage questioning the safety of the HPV vaccination, a rapid decline in HPV vaccination coverage was observed. An information campaign was therefore launched in May 2017 to address HPV vaccination hesitancy. THE SOCIAL MEDIA STRATEGY: 'Heart-brain communication' combined facts and emotions through varied content. Community management guidelines were worked out to ensure that there was positive dialogue. Key Point Indicators (KPI) for Engagement Rate (ER) and Click Through Rate (CTR) were chosen to uphold engagement and traffic from Facebook to the website. The KPIs were used to measure effectiveness. In January 2019, the social media campaign had reached 8,020,000 people with an average of 127 comments per post. The average ER from May 2017 to halfway through 2018 was 6.07% and the CTR was 2.09%. The content subgroup personal stories was the most effective in creating positive dialogue. One year after the launch of the campaign, the number of positive comments had increased from less than 50% to approximately 75%. A comprehensive social media strategy using 'heart-brain communication' proved useful in a campaign for HPV vaccination. The success of the social media strategy was due to meticulous planning prior to launching the campaign, the use of content subgroups, the allocation of adequate resources for community management, the empirical analysis of content, and the use of evaluation results as guidance for the production of new content. Copyright © 2020 Elsevier Ltd. All rights reserved.