---
title: "Health Misinformation"
description: "The feed cannot tell a remedy from a rumour. It can only tell what holds attention — and false health claims hold attention well."
url: https://attentionmachine.org/en/symptoms/health-misinformation/
lang: en
updated: 2026-10-25
license: "CC BY-NC-SA 4.0 (https://creativecommons.org/licenses/by-nc-sa/4.0/)"
---

# Health Misinformation

Health advice travels on the same engagement signals as everything else. The feed cannot tell a remedy from a rumour — only what holds attention. Alarming and contrarian claims hold it well.

## It started before the feed

The clearest case study predates social media. In 1998 a paper in _The Lancet_ claimed a link between the MMR vaccine and autism. It was wrong. Investigation later showed the data had been manipulated[^src-godlee-2011] and that the lead author had undisclosed financial interests; The Lancet fully retracted the paper in 2010[^src-lancet-2010] and the author was struck off the UK medical register. There is no link between the MMR vaccine and autism — this is settled, not contested.

But the retraction took twelve years, and by then the claim had travelled the world and depressed vaccination rates[^src-godlee-2011]. This is the pattern the Journalism and Science pages describe: a false claim moves fast, the correction arrives slowly and travels less far. Health misinformation did not need an algorithm to do harm. The algorithm made the asymmetry worse.

## The infodemic

When COVID-19 arrived, the World Health Organization described the parallel wave of false and misleading claims[^src-world-health-2020] as an infodemic. It was not a metaphor for inconvenience. The WHO[^src-who-2019] had already, in 2019, listed vaccine hesitancy among its top ten threats to global health — at a time when vaccination prevents an estimated two to three million deaths a year. Engagement-optimised feeds amplified the most emotionally charged health content, and [a frightening or contrarian claim tends to outperform](https://attentionmachine.org/en/attention-machine/your-brain/) calm, accurate guidance.

> **Infodemic**
>
> A term the WHO and UN used during COVID-19 for "an overabundance of information, both online and offline", including deliberate attempts to spread wrong information. The point of the word is the _scale and speed_: the problem is not that false health claims exist, which they always have, but that the feed distributes them at the velocity of a pandemic.
>
> **Sources**
>
> - [WHO et al. — _Managing the COVID-19 infodemic: Promoting healthy behaviours and mitigating the harm from misinformation and disinformation_](https://www.who.int/news/item/23-09-2020-managing-the-covid-19-infodemic-promoting-healthy-behaviours-and-mitigating-the-harm-from-misinformation-and-disinformation).

## What the evidence shows it does

This is one of the few places where the causal evidence is strong rather than correlational. In a randomised controlled trial in the UK and USA, researchers showed people either factual information or recent online misinformation about a COVID-19 vaccine. Brief exposure to the misinformation lowered intent to vaccinate[^src-loomba-2021] by about six percentage points in both countries, among people who had said they would "definitely" accept a vaccine. Notably, misinformation that _sounded_ scientific — citing made-up studies and statistics — was the most persuasive.

The route is not only the social feed. A controlled experiment manipulating search-engine results[^src-allam-2014] found that changing which websites a search surfaces — leaning the results pro- or anti-vaccination — measurably shifted people's beliefs and attitudes, and that users were largely unaware the selection was steering them. The same mechanism that decides what you scroll past decides what you find when you go looking for answers.

## No conspiracy. Manufactured doubt — and honest worry.

Two things are true at once, and the page holds both. First, some health misinformation is manufactured doubt: contrarian claims deliberately produced and amplified to make a settled question look unresolved — the same playbook the tobacco and fossil-fuel industries used[^src-oreskes-2010], documented on the Science page. Second, most of the people _sharing_ health misinformation are not malicious. They are worried — about a child, a diagnosis, a side effect — and are seeking answers in the place that answers everything else. The US Surgeon General's 2021 advisory[^src-surgeon-general-2021], which called health misinformation an "urgent threat," is careful to draw exactly this line between deliberate deception and honest questioning.

> **Manufactured doubt**
>
> A strategy, not a state of knowledge: funding and amplifying contrarian claims to make a settled question look unresolved, so that action is delayed and trust is eroded. Oreskes and Conway traced the same small playbook from tobacco to climate. In health, the goal is rarely to prove a competing truth — only to manufacture enough apparent controversy that "the science isn't settled" sounds reasonable when it is.
>
> **Sources**
>
> - Oreskes, N. & Conway, E.M. (2010), _Merchants of Doubt_, Bloomsbury.

## The cost

The harm is not abstract. Reported measles cases worldwide reached 869,770 in 2019[^src-who-2020] — the most since 1996 — and deaths rose by half between 2016 and 2019. The WHO puts the surge down to children not being vaccinated on time, a gap in coverage with many causes; misinformation is one of the reasons people decline a vaccine, not the explanation for the global figure. Health misinformation also leads people to refuse effective treatment: patients who chose alternative medicine alone for curable cancers were two and a half times as likely to die[^src-johnson-2018] within the study period as those who had conventional treatment. News coverage need not be false to do harm: in a nationwide Danish study, more people stopped taking statins early after negative news stories about the drugs[^src-nielsen-2016], and stopping early was associated with more heart attacks and deaths from cardiovascular disease. Misinformation also leads people to harass the health workers[^src-surgeon-general-2021] trying to communicate accurate guidance. The mechanism is the same one running through this whole site: a system that rewards what is engaging, not what is true, distorts how people weigh risk — and with health, the cost of a distorted risk picture can be measured in lives.

**How we know — what is settled, what is genuinely uncertain, and the honest line we hold**

Getting this topic right requires keeping three categories apart. **Settled (refuted, not contested):** vaccines are safe and effective, and the MMR–autism link is false — established by the retraction of the original fraudulent paper[^src-lancet-2010] and by very large subsequent studies: a Danish cohort of 657,461 children[^src-hviid-2019] and a meta-analysis of cohort studies covering 1,256,407 children[^src-taylor-2014]. Treating that as an open question is itself misinformation. **Genuinely uncertain and openly monitored:** like all medicines, vaccines have real side effects, most of them minor, with the rare serious ones tracked by safety-surveillance systems. Saying so is not a concession to anti-vaccine claims — it is the honesty that distinguishes science from doubt-manufacturing, and pretending vaccines have zero risk feeds the "they're hiding something" narrative. **The strategy:** manufactured doubt exploits the gap between those two by inflating the rare and monitored into the catastrophic and concealed.

**On concentration.** The Center for Countering Digital Hate reported in 2021[^src-center-countering-2021] that a small number of accounts ("the Disinformation Dozen") produced a large share of anti-vaccine content on the major platforms. We mention it because it illustrates how amplification can concentrate, but the specific figure was disputed by Meta[^src-bickert-2021] and the analysis is from an advocacy group, so we treat it as suggestive rather than settled — the spine of this page rests on the peer-reviewed and official sources above. The antidote is the one the rest of the site argues for: trusted, correction-transparent sources (a doctor, the systematic reviews on the Tools page) and learning to recognise the technique of manufactured doubt, rather than trying to chase down every individual false claim.

## Sources

[^src-lancet-2010]: [The Lancet (2010), _Retraction — Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children_](https://www.thelancet.com/journals/lancet/article/PIIS0140-6736\(10\)60175-4/abstract).

[^src-who-2019]: [WHO — _Ten threats to global health in 2019_](https://www.who.int/news-room/spotlight/ten-threats-to-global-health-in-2019) (vaccine hesitancy).

[^src-loomba-2021]: Loomba, S., de Figueiredo, A., Piatek, S.J., de Graaf, K. & Larson, H.J. (2021), [_Measuring the impact of COVID-19 vaccine misinformation on vaccination intent in the UK and USA_](https://www.nature.com/articles/s41562-021-01056-1), Nature Human Behaviour 5.

[^src-allam-2014]: Allam, A., Schulz, P.J. & Nakamoto, K. (2014), [_The Impact of Search Engine Selection and Sorting Criteria on Vaccination Beliefs and Attitudes_](https://www.jmir.org/2014/4/e100/), Journal of Medical Internet Research 16(4).

[^src-johnson-2018]: Johnson, S.B., Park, H.S., Gross, C.P. & Yu, J.B. (2018), [_Use of Alternative Medicine for Cancer and Its Impact on Survival_](https://doi.org/10.1093/jnci/djx145), JNCI 110(1) — hazard ratio 2.50 for alternative medicine alone versus conventional treatment.

[^src-surgeon-general-2021]: [US Surgeon General (2021), _Confronting Health Misinformation_](https://www.hhs.gov/sites/default/files/surgeon-general-misinformation-advisory.pdf).

[^src-who-2020]: WHO (12 November 2020), [_Worldwide measles deaths climb 50% from 2016 to 2019_](https://www.who.int/news/item/12-11-2020-worldwide-measles-deaths-climb-50-from-2016-to-2019-claiming-over-207-500-lives-in-2019) — 869,770 cases in 2019, the highest since 1996; the surge attributed to "a failure to vaccinate children on time with two doses of measles-containing vaccines".

[^src-oreskes-2010]: Oreskes, N. & Conway, E.M. (2010), _Merchants of Doubt_, Bloomsbury.

[^src-godlee-2011]: Godlee, F., Smith, J. & Marcovitch, H. (2011), [_Wakefield's article linking MMR vaccine and autism was fraudulent_](https://doi.org/10.1136/bmj.c7452), BMJ 342:c7452.

[^src-world-health-2020]: World Health Organization et al. (23 September 2020), [_Managing the COVID-19 infodemic: Promoting healthy behaviours and mitigating the harm from misinformation and disinformation_](https://www.who.int/news/item/23-09-2020-managing-the-covid-19-infodemic-promoting-healthy-behaviours-and-mitigating-the-harm-from-misinformation-and-disinformation).

[^src-nielsen-2016]: Nielsen, S.F. & Nordestgaard, B.G. (2016), [_Negative statin-related news stories decrease statin persistence and increase myocardial infarction and cardiovascular mortality: a nationwide prospective cohort study_](https://doi.org/10.1093/eurheartj/ehv641), European Heart Journal 37(11), 908–916.

[^src-hviid-2019]: Hviid, A., Hansen, J.V., Frisch, M. & Melbye, M. (2019), [_Measles, Mumps, Rubella Vaccination and Autism: A Nationwide Cohort Study_](https://doi.org/10.7326/M18-2101), Annals of Internal Medicine 170(8) — 657,461 Danish children; no increased risk.

[^src-taylor-2014]: Taylor, L.E., Swerdfeger, A.L. & Eslick, G.D. (2014), [_Vaccines are not associated with autism: an evidence-based meta-analysis of case-control and cohort studies_](https://doi.org/10.1016/j.vaccine.2014.04.085), Vaccine 32(29) — cohort studies of 1,256,407 children.

[^src-bickert-2021]: Bickert, M. (Meta, 18 August 2021), [_How We're Taking Action Against Vaccine Misinformation Superspreaders_](https://about.fb.com/news/2021/08/taking-action-against-vaccine-misinformation-superspreaders/) — Meta's reply: the twelve accounts were "responsible for about just 0.05% of all views of vaccine-related content on Facebook".

[^src-center-countering-2021]: Center for Countering Digital Hate (March 2021), [_The Disinformation Dozen_](https://www.counterharm.com/research/the-disinformation-dozen).

[What you can do →](https://attentionmachine.org/en/educate/what-to-do/)\
[Where to get help →](https://attentionmachine.org/en/educate/get-help/)\
[The Manosphere →](https://attentionmachine.org/en/symptoms/manosphere/)\
[What is Truth? — Science →](https://attentionmachine.org/en/truth/science/)

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