Decline in HPV-Vaccination Uptake in Denmark - The Association between HPV-related Media Coverage and HPV-Vaccination

In 2014, Denmark experienced a rapid decline in vaccination uptake for the human papillomavirus (HPV) vaccine after a successful introduction of the vaccine in 2009. The decline followed negative public attention from 2013 coinciding with increasing suspected adverse-event reporting to the Danish Medicines Agency. The aim of this study was to describe the decline in the uptake of HPV vaccination and to explore the relationship between media coverage, Google searches, and vaccination activity under the hypothesis that media coverage affects search activity and vaccination uptake.

To identify a potential change in the relationship between media coverage and vaccination uptake, the researchers analysed changes in Pearson's correlation, which quantifies to what extent the change in one signal coincides with changes in another.

The vaccination uptake for the first dose of HPV vaccine increased from 80% to 92% for the birth cohorts of 1993 to 2000. For girls born after 2000, the initiation of HPV vaccination decreased for successive birth cohorts, reaching the lowest uptake of 42% for the birth cohort of 2004 (data per June 2017). Figure 2 shows HPV vaccination activity, HPV-related media coverage and search activity from January 2009 to January 2016. As illustrated in the figure, from the middle of 2012 to middle of 2013, there was a marked increase in both search activity and media coverage, which coincided with a drop in vaccination initiation.

The researchers identified July 2013 as a changing point in the relationship between media coverage and vaccination uptake. At that time, there was a negative Pearson's correlation of -0.52. The changing point coincides with both an increase in Google searches for "HPV side effects" and media coverage with negative content.

The timeline in Figure 2 shows the public initiatives and selected significant media events regarding the HPV-vaccine in Denmark 2009-2013. A steep rise in media coverage and search activity was seen after the death of a young actor from cervical cancer in December 2012. In 2013, two series of critical articles in nationwide newspapers questioned the reliability of professional recommendations and later suspected adverse events. Several patient organisations were formed, such as "HPV-Update" under the Danish Association of the Physically Disabled, comprising parents believing that their daughters suffered from adverse events after HPV vaccination. A March 2015 TV documentary, "De vaccinerede piger" ("The Vaccinated Girls") depicted a group of girls reporting a diverse array of symptoms perceived as adverse events following HPV vaccination. This documentary was widely discussed in the media and on social media platforms, coinciding with increased search activity. In the same period, the chairperson of the Health Committee in the Danish Parliament voiced great concern about the safety of the HPV vaccine. Issues of vaccination safety kept resurfacing in the media, such as the freely available newspaper MetroXpress, which had a daily feature page along with a webpage on the "HPV case" (Danish: HPV-sagen). The Danish safety signal was raised to the European Medicines Agency (EMA) Pharmacovigilance Risk Assessment Committee (PRAC) in September 2013. Ultimately, in 2015, the Danish National Board of Health reaffirmed the favourable risk/benefit balance of HPV vaccination in a public statement.

The researchers reflect on the fact that media is part of what shapes parents' impressions of the safety of a vaccine, which is the largest concern parents have today regarding vaccines. A greater belief in the protection offered by childhood vaccines has been found to correlate with acceptance of HPV vaccines. Parent socio-economical and social-environmental factors, including cultural beliefs and social group norms, may also play a role. This influence of social group norms could explain the rapid decline in vaccination seen in this study. Both individual factors, as well as social group norms, can be influenced by massive media coverage and impact parental vaccination choices through different pathways.

According to the researchers, if providers and parents become more cautious during periods of controversy, the health authorities need to be aware of this. For many parents, vaccination decision-making is complex, and providing recommendations from authorities is not enough to safeguard a vaccination programme. Close monitoring of media and public sentiment might allow for early detection of emerging problems - enabling timely action - and this information can be used in shaping communication activities. A strategy for handling a sudden change in public opinion reflected in media could prove vital for reaching and maintaining the optimal vaccination uptake. This is also important to keep in mind when planning the introduction of potential new vaccines into a childhood vaccination schedule. Listening to the public should be a fundamental element of any introduction of a new vaccine.

The World Health Organization (WHO) has developed an e-learning module for crisis communication, including a case study on how a potential HPV vaccine crisis was averted in the United Kingdom (UK). In Denmark, the National Health Authority together with the Danish Cancer Society and other stakeholders launched an informational HPV campaign in 2017, using as the key platform a Facebook page where professionals engage with the public in a timely manner. The Facebook page also directs traffic to an information homepage www.stophpv.dk with additional material.

In short, allegations regarding vaccine-related adverse events need to be dealt with rapidly and effectively so that they do not undermine confidence in the vaccine. Managing inaccurate perceptions of vaccination risks is as important as handling scientifically confirmed risks. Media monitoring may represent an important tool in future monitoring and assessment of confidence in vaccination programmes.