The COVID-19 pandemic, a health crisis of unprecedented scale in the 21st century, was accompanied by an equally significant and dangerous phenomenon—an infodemic. The World Health Organization defines an infodemic as the rapid spread and overabundance of information—both accurate and false—that occurs during an epidemic [1]. A tidal wave of misinformation, disinformation, and rumors characterized the infodemic during the COVID-19 pandemic. This led to widespread confusion, mistrust in health authorities, noncompliance with health guidelines, and even risky health behaviors [2-4].

Moreover, the role of political leaders in shaping the narrative around COVID-19 policies significantly influenced these dynamics. In countries such as the United States, Brazil, and Turkey, the intersection of political ideology and crisis management led to increased societal polarization. Leaders in these nations used communication strategies ranging from denying the severity of the pandemic to promoting unproven treatments [5,6]. This complex interplay between leadership communication and public response underscores the critical need for science-based policy communication and the responsible use of social media platforms to combat misinformation and foster societal unity in the face of a global health crisis.

Furthermore, the emergence of the COVID-19 infodemic highlighted the crucial role of social media literacy in combating misinformation. Educating the public on discerning credible information on the web has emerged as a pivotal strategy for mitigating the spread of misinformation and its consequences [7].

Misinformation during public health crises has been a recurring problem. Historical examples from the Ebola outbreak, such as rumors that the virus was a government creation or that certain local practices could cure the disease, highlight how misinformation can hinder public health responses [8]. False beliefs, such as that drinking salt water would cure Ebola or that the disease was spread through the air, led to a mistrust of health workers and avoidance of treatment centers, exacerbating the crisis [9]. In the context of COVID-19, misinformation was particularly pervasive, with false claims about the effectiveness of various nostrums, leading to panic buying and shortages [3,10]. The impact of such misinformation varied across regions [4,11]. These dynamics were often fueled by psychological and social factors, including fear, uncertainty, and the reinforcing nature of social media algorithms, which created echo chambers of false information [12,13]. The wide-ranging consequences affected not only immediate health behaviors but also the trust in, and response to, public health authorities [2,14].

Misinformation during a public health crisis is nothing new. However, the scale and speed at which misinformation spread during the COVID-19 pandemic are unparalleled. This situation was exacerbated by the widespread use of social media and the internet, where rumors can rapidly reach large audiences [9,15]. This spread of misinformation had far-reaching consequences: it undermined public health efforts, promoted harmful practices, contributed to vaccine hesitancy, and possibly prolonged the pandemic [8,10,12,16]. These effects went beyond individual health behaviors; they influenced public health policies and diminished trust in health authorities and the scientific community [12,17,18].

In light of these challenges, the machine learning–enhanced graph analytics (MEGA) framework has emerged as a novel approach to managing infodemics by leveraging the power of machine learning and graph analytics. This framework offers a robust method for detecting spambots and influential spreaders in social media networks, which is crucial for assessing and mitigating the risks associated with infodemics. Such advanced tools are essential for public health officials and policy makers to navigate the complex landscape of misinformation and to develop more effective communication strategies [19]. Furthermore, combating this infodemic necessitates a strategic approach encapsulating the “Four Pillars of Infodemic Management”: (1) monitoring information (infoveillance) to track the spread and impact of misinformation; (2) enhancing eHealth literacy and science literacy, empowering individuals to evaluate information critically; (3) refining knowledge quality through processes such as fact checking and peer review, ensuring the reliability of information; and (4) ensuring timely and accurate knowledge translation, minimizing the distortion by political or commercial interests [20]. These measures are essential for mitigating the impact of misinformation and guiding the public and professionals toward quality health information during the pandemic and beyond. The COVID-19 pandemic has highlighted the need for improved public health communication and preparedness strategies, particularly in countering misinformation to prevent similar challenges in future health crises [15,21].

Recognizing the unique challenges posed by the COVID-19 infodemic, this comprehensive scoping review seeks to systematically explore various dimensions of misinformation related to the pandemic. Our investigation is informed by a critical analysis of existing literature, noting a gap in studies that collectively examine the themes, sources, target audiences, impacts, interventions, and effectiveness of public health communication strategies against COVID-19 misinformation. To the best of our knowledge, this is the first review that attempts to bridge this gap by providing a comprehensive and integrated analysis of these key dimensions. While individual aspects of misinformation have been addressed in prior research, there lacks a comprehensive review that integrates these components to offer a holistic understanding necessary for effective countermeasures. Therefore, our review is structured around four pertinent questions, each carefully selected for their significance in advancing our understanding of the COVID-19 infodemic and its counteraction:

These questions were selected to emphasize critical areas of COVID-19 misinformation that, when addressed, can significantly contribute to bridging technical and knowledge gaps in our response to current and future public health emergencies. By detailing our study’s contributions to existing literature, we aim to present distinctive understandings crucial for policy makers, health professionals, and the public in effectively addressing misinformation challenges.

The literature search targeted 3 major databases: MEDLINE (PubMed), Embase, and Scopus. These databases were selected for their comprehensive coverage of medical, health, and social science literature. The search strategy was crafted using a combination of keywords and subject headings related to COVID-19, misinformation, and public health communication. We used (“COVID-19” OR “SARS-CoV-2” OR “Coronavirus”) AND (“Misinformation” OR “Disinformation” OR “Fake news” OR “Infodemic”) AND (“Public health outcomes” OR “Health impacts”) AND (“Communication strategies” OR “Public health communication”).

The inclusion and exclusion criteria are presented in Textbox 1.

The study selection process involved an initial screening of titles and abstracts to eliminate irrelevant studies, followed by a thorough full-text review of the remaining articles. This critical stage was conducted by the authors, each with expertise in public health communication and health services research, thereby enhancing the thoroughness and reliability of the selection process. In cases of disagreement, the reviewers engaged in discussions until a consensus was reached on the inclusion of each article. In addition, we adhered to the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews) guidelines [18] to enhance the thoroughness and transparency of our review (see Multimedia Appendix 1 for the PRISMA-ScR checklist).

A total of 390 articles were identified from the 3 databases, of which, after removing 134 (34.4%) duplicates, 256 (65.6%) articles remained. Of these 256 articles, 69 (27%) were selected based on abstract searches. Of the 69 full-text articles, 27 (39%) were assessed for eligibility. Of these 27 studies, 21 (78%) were included in the scoping review (Figure 1). This analysis of the 21 studies provides a comprehensive overview of the many impacts of misinformation during the COVID-19 pandemic, including its characteristics, themes, sources, effects, and public health communication strategies.

The included studies exhibited considerable diversity in terms of their methodologies, geographic focus, and objectives (Table 1). Verma et al [15] conducted a large-scale observational study in the United States, analyzing social media data from >76,000 users of Twitter (subsequently rebranded X) to establish a causal link between misinformation sharing and increased anxiety. By contrast, Loomba et al [11] carried out a randomized controlled trial in both the United Kingdom and the United States to examine the impact of misinformation on COVID-19 vaccination intent across different sociodemographic groups. In the United States, Bokemper et al [22] used randomized trials to assess the efficacy of various public health messages in promoting social distancing. Xue et al [23] used observational methods to explore public attitudes toward COVID-19 vaccines and the role of fact-checking information on social media. These studies collectively used quantitative analysis, web-based surveys, cross-sectional studies, and social network analysis, reflecting the diversity of research approaches. Sample sizes ranged from hundreds to tens of thousands of participants, providing a broad view of the infodemic’s impact. Notably, most of the studies (17/21, 81%) were conducted on the web, underlining the infodemic’s digital nature. The outcomes assessed various public health aspects, including mental health, communication effectiveness, and behavior change. Kumar et al [13] used social network and topic modeling analyses to gain insights into public perceptions on Reddit, contributing to the methodological diversity within the reviewed literature.

Our study underscores the profound influence of misinformation during the COVID-19 pandemic, particularly in shaping public responses. Misinformation, primarily propagated through social media, led to widespread misconceptions about the severity of COVID-19 infection, triggering public confusion, reluctance to adhere to health guidelines, and increased vaccine hesitancy. This phenomenon significantly impacted vaccine uptake rates. Gallotti et al [33] highlighted the simultaneous emergence of infodemics alongside pandemics, underlining the critical role of both human and automated (bots) accounts in spreading information of questionable quality on platforms such as Twitter. The authors introduced an Infodemic Risk Index to measure the exposure to unreliable news, showing that the early stages of the COVID-19 pandemic saw a significant spread of misinformation, which only subsided in favor of reliable sources as the infection rates increased [33]. This emphasizes the complex challenge of managing infodemics in tandem with biological pandemics, necessitating adaptive public health communication strategies that are responsive to evolving information landscapes. Our findings resonate with historical observations in public health crises, evidenced by studies on the Zika virus outbreak [34], polio vaccination efforts in India and Nigeria [35], and the Middle East respiratory syndrome outbreak [36]. Similar patterns of misinformation were also noted in the H1N1 pandemic and the Ebola outbreak. These instances highlight the critical need for clear, proactive communication strategies to effectively manage misinformation and guide public understanding and responses.

The review also reveals a predominant focus on digital misinformation, underscoring the necessity to comprehend the impact of traditional media and word-of-mouth communication in spreading misinformation. While studies such as that by Basch et al [37] have started to address this gap, there is a clear need for more extensive research, particularly on the long-term effects of misinformation on public health behaviors after a pandemic. This shift toward credible information, as observed by Gallotti et al [33], signals an opportunity for future research to explore capitalizing on changing information consumption patterns in public health messaging. Such observations are crucial for developing effective communication strategies, highlighting the necessity of integrating infodemic management with pandemic response efforts to mitigate misinformation effects and guide public behavior appropriately. The disparity in the effectiveness of misinformation mitigation strategies points to the need for a nuanced understanding of how misinformation evolves over time. Studies, such as that by Vijaykumar et al [38], highlight the challenges in countering rapidly changing misinformation narratives on digital platforms. Further investigation into the effectiveness of fact checking across different cultures and demographics, as suggested by Chou et al [39], is essential for developing better strategies to combat misinformation in diverse settings.

This review found that various factors, including delayed communication from health authorities, cognitive biases, sociodemographic characteristics, trust in official sources, and political orientation, played a significant role in the spread of misinformation during the pandemic. These findings align with similar observations in other studies. Eysenbach [40] emphasized the importance of trust in government agencies and health care providers in shaping individuals’ beliefs and their willingness to share accurate information during public health crises. In addition, Pennycook and Rand [41] highlighted how political beliefs and affiliations can influence people’s interpretation of information, thus impacting their acceptance or rejection of official guidance during public health crises. The study by Gallotti et al [33] also highlighted the differentiated roles of verified and unverified users on social media in propagating COVID-19–related information. Their analysis shows that verified users began to point more toward reliable sources over time, hinting at the potential of leveraging social media influencers and verified accounts in directing public attention to factual and scientifically verified information [33].

These insights indicate the critical need for dynamic public health strategies that are adaptable and actionable, aimed at curtailing misinformation through education and technology. It is essential to incorporate digital literacy and clear, audience-specific messaging to effectively counter misinformation, a strategy that has proven successful in health crises beyond the COVID-19 pandemic; for example, during the H1N1 pandemic, targeting specific audience segments with tailored messages significantly improved public understanding and guideline compliance [42]. Likewise, during the Ebola outbreak, proactive and transparent strategies were key in dispelling rumors and building trust in public health authorities [43]. These approaches, based on an understanding of the target audience’s concerns and media habits, are consistent with our findings where digital literacy and targeted messaging played a critical role in mitigating COVID-19 misinformation effects. Such strategies are vital not only for immediate crisis response but also for fostering long-term resilience in public health communication, helping to enable the public to distinguish credible information from misinformation, with the ultimate goal of enhancing public health outcomes and trust in health authorities.

In examining the authoritarian responses to the pandemic, particularly in Brazil and Turkey, it is evident that leadership tactics significantly contributed to societal polarization and misinformation. Leaders in these countries used the crisis to suppress dissent and consolidate power, often spreading misinformation and underreporting COVID-19 cases, thereby exacerbating public mistrust and confusion [5]. Similarly, a study of communication strategies across countries with high rates of infection emphasized the variation in political leaders’ approaches, where strategies ranged from science-based communications to ideologically influenced messaging [6]. The study highlighted the potential for political leaders to influence public health responses through their communication tactics, further impacting public behavior and trust in health guidelines [6]. In certain situations, the integration of political ideology with public health messaging, as observed in countries such as the United States, Brazil, India, and the United Kingdom, not only perpetuated misinformation but also intensified societal rifts [5,6]. This highlights the paramount role of leadership in navigating public health crises; for instance, in the United States and Brazil, political leaders’ approaches to the COVID-19 pandemic—characterized by mixed messaging on mask wearing and social distancing—contributed to public confusion and a politicized response to the pandemic. Similarly, the initial underestimation of the virus’s impact in India and the United Kingdom’s delayed lockdown response serve as examples of how political decisions can shape public health outcomes and trust in health authorities, emphasizing the profound impact of aligning political views with public health communication [5,6]. In addition, the initial reluctance of the World Health Organization to endorse mask wearing, social distancing, and handwashing, followed by a later reversal of these recommendations, exemplifies the challenges and confusion created by global health leadership during the early stages of the pandemic [44]. Such shifts in guidance contributed to the global spread of misinformation, further complicating public health responses and trust in international health authorities [6]. These approaches, based on an understanding of the target audience’s concerns and media habits, are consistent with our findings that digital literacy and targeted messaging played a critical role in mitigating COVID-19 misinformation effects. Such strategies are vital not only for immediate crisis response but also for fostering long-term resilience in public health communication, helping to enable the public to distinguish credible information from misinformation, with the ultimate goal of enhancing public health outcomes and trust in health authorities. Applying the MEGA framework in practical settings could revolutionize public health communication, offering a model for how technology can be harnessed to tackle misinformation more effectively. By processing massive graph data sets and accurately computing infodemic risk scores, MEGA supports the development of targeted communication strategies and interventions. Its approach to preserving crucial feature information through graph neural networks signifies a leap forward in optimizing learning performance, underscoring the framework’s utility in crafting evidence-based policies and initiatives to effectively combat misinformation. This emphasizes the importance of integrating advanced technological solutions, such as MEGA, into public health strategies to enhance the precision and effectiveness of infodemic management [19]. The integration of social media literacy into public health strategies is emphasized as essential by Ziapour et al [7], suggesting that a populace equipped with advanced media literacy skills exhibits greater resilience against misinformation.

Our study reveals the profound impact of the COVID-19 infodemic, which extended beyond public health and eroded trust in health institutions and government authorities. This decline in trust contributed to societal polarization, mirroring the effects seen in the Ebola outbreak, where misinformation led to notable repercussions [45,46]. Further research, similar to that conducted on the Zika outbreak by Basch et al [37], is needed to understand the long-term effects of misinformation on societal cohesion and trust. Addressing this evolving landscape of misinformation requires dynamic and adaptable public health policies. These strategies should integrate insights from various methodologies, using both digital and traditional media for greater reach and impact, drawing lessons from the successful strategies deployed during the H1N1 pandemic, such as those highlighted by Chou et al [39].

Our study advocates for a collaborative approach, uniting governments, the private sector, and the public in a concerted effort to combat misinformation, highlighting the importance of joint action in this global challenge. This approach should include continuous monitoring of misinformation trends, implementing regular fact checking, taking legal action against sources of misinformation, and developing specific communications to debunk myths. Similar findings have been reported in studies addressing misinformation related to the Zika virus [34,47], yellow fever [48], and Ebola [49], emphasizing the importance of a holistic strategy involving all stakeholders [50].

The review has several limitations to consider. First, there is a temporal limitation because it included only studies published between December 2019 and September 2023, potentially excluding more recent research that could have offered additional insights. Second, the reliance on specific databases (MEDLINE [PubMed], Embase, and Scopus) as the primary sources for data might have led to the omission of pertinent studies that are not indexed in these databases. Third, the study’s sole focus on research articles may have excluded valuable insights from other scholarly works such as conference papers, theses, case studies, and gray literature. Finally, it is important to acknowledge that the study’s restriction to English-language publications may have excluded valuable research conducted in other languages. While efforts were made to review the available literature comprehensively, omitting non-English sources could limit the breadth and depth of the findings. Recognizing these limitations, future endeavors should aim to expand the scope of research beyond these constraints, incorporating a more diverse range of sources, languages, and real-world interventions to enrich our understanding of, and response to, misinformation.

The results of this review emphasize the significant and complex challenges posed by misinformation during the COVID-19 pandemic. It shows how misinformation can have a wide impact on public health, societal behaviors, and individual mental well-being. The findings highlight the critical role of effective public health communication strategies in addressing the infodemic. It is essential that these strategies are not only targeted and precise but also adaptable and inclusive, ensuring that they are relevant to diverse demographic and sociocultural contexts.

The review also emphasizes the need for ongoing collaborative research efforts to further explore the nuances of the misinformation spread and its consequences. This requires cooperation among health authorities, policy makers, communication specialists, and technology experts to develop evidence-based approaches and policies to combat misinformation.

Furthermore, the review highlights the importance of refining public health communication strategies to keep up with the ever-changing nature of misinformation, especially in the digital realm. It advocates using advanced technology and data-driven insights to enhance the reach and impact of health communication. By combining scientific rigor, technological innovation, and empathetic communication, these strategies can contribute to building public trust, promoting health literacy, and creating resilient communities capable of recognizing and countering misinformation.

In summary, the lessons learned from the COVID-19 pandemic emphasize the necessity of strengthening public health communication infrastructures. This strengthening is vital for addressing the current misinformation crisis and preparing for future public health emergencies. Implementing these recommendations will play a crucial role in shaping a more informed, aware, and health-literate global community better equipped to confront the challenges posed by misinformation in our increasingly interconnected world. Furthermore, future research directions should explore integrating advanced large language models with frameworks similar to MEGA. This exploration will bolster automated fact checking and infodemic risk management, contributing to more effective strategies in combating misinformation in public health communication.