The WHO Regional Office for the Western Pacific has taken steps to explore the role and potential of dark social communication for promoting health messages and reducing the spread of misleading information during and between influenza pandemics.‘Dark social’ refers to internet traffic outside the scope of most analytical tracking. It describes people’s interaction and sharing activities on private channels such as messaging apps, email and text messages. The private nature of the dark social is a challenge for multisource social listening, which allows Member States, WHO, and partners to gather the insights of and feedback from target audiences and other sources; determine the strengths and weaknesses of risk communication tools and tactics; identify key community concerns, myths, and misunderstandings; and assess risk perceptions, knowledge, and behaviours. Listening is particularly important during pandemics, when the “infodemic” – the sheer volume of information, often with conflicting messages – can leave many communities confused and unsure of what actions to take.According to Kepios[1], in October 2022, there were an estimated 4.74 billion users of various social media platforms worldwide. Out of these, 2 billion are active on WhatsApp, 1.29 billion on WeChat/Weixin, and 976 million on Facebook messenger. The sheer number of dark social users makes it imperative to discover how different communities use dark social platforms, as well as how dark social networks can be used to improve the Western Pacific’s influenza preparedness and response.WHO has conducted preliminary research on the use of messaging applications and existing privacy policies of popular dark social networks in the region as part of its work under the Pandemic Influenza Preparedness (PIP) Framework Partnership Contribution. The research also involved examining people’s daily access to and consumption of health-related news and information. Consultations with eight WHO Country Offices were held to identify gaps in the available information and determine how the Regional Office could support Country Offices and Member States to incorporate dark social into current communication strategies and emergency preparedness and response frameworks. The research indicates that the accessibility and ease of use of dark social platforms make the technology a good instrument for optimizing the spread of accurate information, facilitating interaction and fostering trust with different communities and groups. Dark social software, such as chatbots, can also be used to receive questions, provide feedback, and gain insights from the general public. When chatbots are integrated into data management platforms, these can help generate reports about emerging misinformation and disinformation and potential outbreaks. To support WHO Country Offices in integrating dark social principles into their current communication and infodemic management efforts, a series of meetings and presentations were conducted in November and December 2022. Activities also involved developing a roadmap to lay out the steps the WHO Regional Office and Country Offices need to take to strengthen engagement in private messaging apps. A practical guideline is also being developed to provide tips on how dark social can be utilized for external communication. Gaining insights into dark social to monitor rumours and address communities’ concerns and information needs is an important element in RCCE for behaviour change, and population behaviour can have a significant impacts on preventing and controlling pandemics.[1] https://kepios.com/