Case Study 14.2: COVID-19 Infodemic — Real-Time Misinformation During a Pandemic

Overview

The COVID-19 pandemic that began in late 2019 was the first pandemic to unfold in the era of social media ubiquity, algorithmic content distribution, and end-to-end encrypted messaging. It was also, by most measures, the largest health misinformation event in history. The World Health Organization declared that an "infodemic" — an overabundance of accurate and inaccurate information — accompanied the pandemic, creating confusion, undermining trust in health authorities, and directly contributing to preventable deaths.

This case study examines the COVID-19 infodemic systematically: the WHO's monitoring framework, the major false claims and their spread patterns, the measurable health consequences, and the institutional responses. It provides the most comprehensive real-time test case available for theories of health misinformation spread and intervention.

Part I: The WHO's Infodemic Framework

What is an Infodemic?

The WHO declared the COVID-19 infodemic in February 2020 — weeks before declaring COVID-19 a pandemic — recognizing that the information crisis was developing at a faster pace than the disease itself. The WHO defined an infodemic as an "overabundance of information, some accurate and some not, that occurs during an epidemic. It makes it hard for people to find trustworthy sources and reliable guidance when they need it."

This definition captures something important: the infodemic is not simply a problem of false information existing. False information has always existed. The infodemic is a problem of false information being produced at scale, distributed at velocity, and competing with accurate information in channels that do not systematically favor accuracy. In a digital information environment where social media algorithms optimize for engagement rather than accuracy, and where the most emotionally alarming content travels fastest, accurate public health information faces severe structural disadvantages.

WHO Infodemic Management

In response, the WHO established an infodemic management program that included:

Myth-busting communications: The WHO's website developed a dedicated myth-busting page that directly addressed major false claims. At peak operation, the page addressed over 50 specific false claims in multiple languages.

EPI-WIN (WHO's Health Emergencies Information and Guidance for COVID-19): A network of partners who committed to rapid amplification of verified health information.

EARS (Early AI-supported Response with Social Listening): A social listening system that monitored social media in multiple languages to identify emerging false claims and concerns.

Partnership with platforms: The WHO partnered with major social media platforms — Google, Facebook, Twitter, YouTube, TikTok, WhatsApp — to promote WHO content and reduce the visibility of contradictory health claims.

The effectiveness of these interventions was mixed. The WHO's communications reached large audiences, but the volume of misinformation dwarfed the capacity of any institutional response. Research on the "information cure ratio" — the ratio of accurate correction to false claim circulation — found that false claims consistently outran corrections by substantial margins.

Part II: Major False Claims and Their Spread Patterns

Category 1: Disease Origin Claims

5G Towers Cause COVID-19

The claim that 5G cellular tower radiation causes COVID-19 emerged in January 2020 in online forums and spread rapidly to mainstream social media. The claim appeared in multiple forms:

  • 5G weakens the immune system, enabling COVID-19 infection
  • 5G is COVID-19 (the radiation produces COVID-like symptoms)
  • Bill Gates and global elites are using 5G and COVID together as a population control mechanism

The claim was biologically impossible: radio waves cannot transmit or create viruses, and 5G radiation is non-ionizing, with demonstrated safety within regulatory exposure limits. It was also epidemiologically refuted by the spread of COVID-19 in areas with no 5G infrastructure.

Despite this, the claim motivated arson attacks on cell towers in the United Kingdom, Netherlands, Belgium, Australia, and other countries. Between March and May 2020, more than 70 cell tower fires were attributed to 5G conspiracy beliefs. At least 15 engineers and telecom workers reported physical assaults by individuals who believed them to be deploying 5G equipment.

The BBC, working with OFCOM (the UK communications regulator), documented the spread pathway: the claim originated in small alternative media outlets and forums, was amplified by celebrities and influencers with large social media followings (most notably British television presenter Eamonn Holmes, who stated on television that the 5G link was "not something" he was "able to dismiss"), was then picked up by mainstream news outlets in the context of debunking (which, per the illusory truth effect, increased exposure to the claim itself), and finally reached millions through WhatsApp group sharing.

Lab Leak vs. Natural Origin

The claim that COVID-19 was engineered in the Wuhan Institute of Virology and released (accidentally or intentionally) was initially treated as a conspiracy theory by major media outlets and social media platforms, which suppressed discussion of it. Facebook, in particular, removed content promoting the lab leak hypothesis in 2020.

The subsequent history of this claim is instructive for understanding the limits of the misinformation/conspiracy theory binary. By 2021-2023, multiple intelligence agencies (including the FBI and Department of Energy) had assessed a lab-related origin as plausible, though not proven. The scientific consensus on the question shifted from strong natural-origin preference to genuine uncertainty.

The lab leak episode illustrates a boundary problem: the lab leak hypothesis was plausible (China's Wuhan Institute of Virology conducts coronavirus research; an accidental release is not biologically implausible) even when it was treated by many fact-checkers as a conspiracy theory. The suppression of the claim by platforms, and its subsequent rehabilitation, significantly damaged the credibility of platform content moderation in the eyes of large sections of the public.

Category 2: Treatment Misinformation

Hydroxychloroquine

President Trump first mentioned hydroxychloroquine as a potential COVID-19 treatment in a March 19, 2020, White House briefing, describing it as a potential "game changer." The claim was based on a small, non-controlled study from France. Trump subsequently mentioned hydroxychloroquine dozens of times at press conferences, on Twitter, and in media interviews.

The impact was immediate and measurable. Hydroxychloroquine prescriptions in the United States increased 46-fold in the two weeks following Trump's first mention. Pharmacies reported shortages. Patients with autoimmune diseases — rheumatoid arthritis, lupus — for whom hydroxychloroquine is a standard, FDA-approved treatment — were unable to fill their prescriptions.

Multiple large randomized controlled trials subsequently demonstrated that hydroxychloroquine had no benefit for COVID-19 treatment or prophylaxis. The WHO's Solidarity trial, the UK RECOVERY trial, and multiple smaller RCTs all found null results. The FDA, which had issued an Emergency Use Authorization for hydroxychloroquine in March 2020 following White House pressure, revoked it in June 2020 after the evidence accumulated.

The damage was not limited to the drug shortage. The hydroxychloroquine episode established a precedent that would be repeated with ivermectin and other claimed treatments: politically promoted, insufficiently tested treatment; accumulation of clinical evidence against it; continued promotion by political actors despite scientific consensus against it; massive public uptake and harm.

Ivermectin

Ivermectin, an antiparasitic drug effective against certain parasitic infections in humans and livestock, became the subject of an organized misinformation campaign beginning in 2020. A network of researchers, physicians, and social media influencers promoted ivermectin as a COVID-19 treatment, citing a body of preliminary studies. The campaign was amplified through a social media ecosystem that included the "FLCCC Alliance" (Front Line COVID-19 Critical Care Alliance), conservative media, and multiple international networks.

An investigation published in Wired in 2021 documented the financial and organizational relationships among key ivermectin promoters and traced the origin of many promotional claims to a single group of researchers with undisclosed financial relationships to pharmaceutical companies interested in ivermectin patents.

The body of clinical evidence supporting ivermectin was subsequently found to be severely contaminated. A key supporting study, conducted in Egypt, was found to be fabricated and was retracted. Multiple other studies were found to have significant quality problems. Andrew Hill, a virologist whose meta-analysis had been widely cited by ivermectin advocates, stated publicly that he had received pressure to produce a favorable analysis from researchers with financial interests in ivermectin.

Multiple large, well-designed randomized trials — including the NIH-sponsored ACTIV-6 trial and the large Brazilian Together trial — found no benefit of ivermectin for COVID-19. The FDA repeatedly warned against the use of veterinary ivermectin formulations by humans. Despite this, ivermectin purchases (including veterinary formulations from farm supply stores) remained elevated throughout 2021 and 2022, and multiple emergency room visits for ivermectin overdose were reported.

Bleach and Disinfectant Ingestion

On April 23, 2020, at a White House coronavirus task force briefing, President Trump suggested that "injection" of disinfectants or "cleaning" the lungs with ultraviolet light might be effective COVID-19 treatments, and asked Dr. Deborah Birx whether medical researchers had looked at such approaches.

The immediate response from poison control centers was documented in real time. A study by Gharpure et al. (2020), published in CDC's Morbidity and Mortality Weekly Report, documented that 4.9% of survey respondents reported having engaged in at least one of the following "high-risk practices" in the past month: washing food with bleach, applying household cleaning or disinfectant products to skin, intentionally inhaling or ingesting cleaning products. The proportion engaged in these practices was significantly higher among those who reported having relied primarily on the federal government for COVID-19 information.

Category 3: Vaccine Misinformation

mRNA Vaccines Alter DNA

The claim that COVID-19 mRNA vaccines alter recipients' DNA was among the most biologically illiterate COVID-19 vaccine myths, yet also among the most persistent. The claim was false on multiple levels: mRNA is not DNA; mRNA is a temporary message that is read by ribosomes and degraded; mRNA does not enter the cell nucleus (where DNA is housed); and even in the hypothetical event that mRNA somehow reached the nucleus, it would require reverse transcriptase (an enzyme present in some viruses but not in human cells) to be converted to DNA. The claim reflected a fundamental misunderstanding of basic molecular biology that could have been addressed by introductory biology education.

Despite this, a 2021 survey found that approximately 40% of unvaccinated Americans believed or were unsure whether COVID-19 vaccines could alter their DNA.

Vaccine Microchips

The claim that COVID-19 vaccines contained government tracking microchips or that the vaccines were vehicles for injecting 5G-enabled surveillance technology merged two prominent conspiracy narratives. It was physically impossible: the 25-gauge needle typically used for vaccination has an internal diameter of approximately 0.25 millimeters, which is too small to inject any functioning electronic device currently manufacturable. The claim nonetheless achieved significant traction.

A YouGov/The Economist survey in May 2021 found that 20% of Americans believed or somewhat believed the microchip claim. International polling found significant minorities in multiple European countries holding the belief. The claim was associated with vaccine refusal and appears to have contributed meaningfully to COVID-19 vaccination rate disparities.

Part III: Measurable Health Consequences

Misinformation and Vaccination Rates

The relationship between COVID-19 misinformation exposure and vaccination behavior was studied extensively. Key findings include:

  • Studies by Roozenbeek et al. (2020) and others found that exposure to specific COVID-19 misinformation claims was associated with reduced vaccination intentions, even controlling for prior vaccine hesitancy.
  • Lazarus et al.'s large multinational survey found substantial variation in vaccination willingness across countries, with vaccine hesitancy highest in countries with high social media use and low institutional trust.
  • A study by Bridgman et al. (2021) estimated that reliance on social media as a primary news source was associated with both higher misinformation exposure and lower vaccination intention.

COVID-19 Deaths Attributable to Misinformation

Estimating the number of COVID-19 deaths attributable to misinformation is methodologically challenging because the causal chain involves multiple steps, each with uncertainty: misinformation exposure reduces vaccination intention; reduced intention reduces vaccination rate below what would otherwise have been achieved; lower vaccination rate increases COVID-19 transmission and mortality. Confounders at each step are numerous.

Despite these challenges, several estimates have been attempted:

  • Kaiser Family Foundation analysis estimated that the vaccination coverage gap between vaccinated and unvaccinated states in the United States (which was closely correlated with partisan politics, which in turn correlated with misinformation exposure) was associated with tens of thousands of preventable COVID-19 deaths between June 2021 and September 2021 alone.
  • Brown et al. (2021) estimated that bringing all U.S. states to the vaccination coverage of the highest-vaccination state could have prevented approximately 300,000 COVID-19 deaths in the period of vaccine availability.
  • While neither of these figures can be attributed entirely to misinformation — political identity, institutional distrust, access barriers, and genuine hesitancy all contribute to the vaccination gap — misinformation was a significant contributing factor.

Part IV: Institutional Responses and Their Effectiveness

Platform Moderation

All major social media platforms implemented some form of COVID-19 health misinformation policy during 2020-2021:

  • Facebook: Removed false claims that could contribute to physical harm; added information labels to COVID-19 content; directed users searching for COVID-19 information to WHO-approved sources. Removed over 12 million pieces of COVID-19 misinformation by May 2020.
  • YouTube: Removed content contradicting WHO guidance; added information panels to COVID-19 videos directing to authoritative sources; demonetized COVID-19 content from creators who spread misinformation.
  • Twitter: Added labels to misleading COVID-19 tweets; required sharing permission before retweeting labeled content; suspended accounts engaged in COVID-19 misinformation.
  • WhatsApp: Limited message forwarding to one chat at a time for messages marked as "frequently forwarded," reducing viral spread.

Research on the effectiveness of these interventions is mixed. Studies have found that information labels reduce the sharing rate of labeled false content, but also produce "implied truth" effects (unlabeled content is perceived as more credible by comparison). Removal is effective for reducing spread of specific content but may increase community cohesion and conspiracy beliefs among affected groups.

Government Response

Government responses to the COVID-19 infodemic ranged from public health communication campaigns to regulatory action against specific misinformation producers to, in some countries, criminalization of specific false health claims.

The United States Surgeon General issued an advisory in July 2021 calling on tech companies to do more to reduce health misinformation, and Congress held hearings on social media's role in amplifying COVID-19 misinformation. No legislation specifically targeting COVID-19 health misinformation was passed, partly due to First Amendment constraints.

Several countries with different legal frameworks — Germany, Singapore, the European Union — imposed or proposed stricter requirements on platforms to remove misinformation, with fines for non-compliance.

Lessons and Implications

What the COVID Infodemic Taught Us

The COVID-19 infodemic provided the largest real-world test case for theories of health misinformation spread and intervention. Key lessons include:

Speed of false information exceeds institutional response capacity. The WHO, CDC, and national health agencies were consistently unable to respond as quickly as misinformation spread. The "first mover advantage" of false claims meant that corrections always chased a moving target.

The lab leak episode shows the limits of "misinformation" as a category. When a claim is plausible but unverified, the mechanisms of misinformation response (suppression, labeling as false) are inappropriate and counterproductive. The infodemic management framework requires more sophisticated category distinctions than "true vs. false."

Misinformation exploits genuine institutional failures. Many COVID-19 false claims gained traction partly because real institutional failures — inconsistent mask guidance, premature pronouncements about vaccine protection duration, opaque communication about vaccine adverse effects — created legitimate grounds for skepticism. Credibility requires ongoing institutional accountability, not just better messaging.

Prebunking at scale is feasible. The COVID-19 pandemic produced the largest prebunking interventions ever tested, including YouTube's partnership with Cambridge's SIREN project to prebunk misinformation techniques, and Google's deployment of prebunking ads. Early results were promising, though full effectiveness evaluation remains ongoing.

Discussion Questions

  1. The WHO declared an infodemic before declaring a pandemic. Does this reflect appropriate prioritization, or does it reflect institutional overemphasis on communication at the expense of direct disease response?

  2. Facebook and YouTube's platform policies suppressed discussion of the lab leak hypothesis in 2020, which was subsequently rehabilitated as a plausible origin theory. What does this episode suggest about the appropriate scope of platform content moderation for uncertain scientific questions?

  3. The bleach ingestion data from Gharpure et al. (2020) found that high-risk hygiene practices were more common among people who reported relying primarily on the federal government for COVID-19 information. What are the implications of this finding for how we understand the relationship between institutional communication and public behavior?

  4. Estimate (with explicit assumptions) how many U.S. COVID-19 deaths might be attributable specifically to vaccine misinformation. What data would you need, and what methodological challenges would you face?

  5. The COVID-19 infodemic response required unprecedented coordination between public health agencies, social media platforms, governments, and civil society organizations. What governance frameworks might institutionalize this coordination for future health crises without the risks of government overreach or platform censorship?

References: WHO Infodemic Management Program (2020-2022); Roozenbeek et al. (2020), Susceptibility to misinformation about COVID-19 across 26 countries; Gharpure et al. (2020), Knowledge and Practices Regarding Safe Household Cleaning and Disinfection for COVID-19 Prevention — United States, May 2020; Lazarus et al. (2021), A global survey of potential acceptance of a COVID-19 vaccine; Kaiser Family Foundation COVID-19 Vaccine Monitor; Brown et al. (2021), Estimating excess mortality from COVID-19; Institute for Strategic Dialogue COVID-19 Disinformation Briefings; CCDH "Disinformation Dozen" report (2021).