How Social Media Is Fueling an Epidemic of Misinformation and Disinformation—and Distrust in Science

A Conversation With Kasisomayajula ‘Vish’ Viswanath, PhD

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The COVID-19 pandemic and the confluence of events that followed—including the rapid development of vaccines, the mixed messaging on mitigation efforts to prevent coronavirus infection, and the growing political polarization—helped spark public mistrust and skepticism toward science. This mistrust has a long history in the United States, especially regarding immunization. The first administration of a vaccine in America was against smallpox in the 1720s, and it so outraged citizens as “antithetical to God’s will,” it launched the antivaccine movement.1 This movement has exponentially grown with the advent of social media both in the United States and globally. According to a report by the Centre for Countering Digital Hate, 31 million people follow anti-vaccine groups on Facebook, with an additional 17 million followers on YouTube.2

Living With the Double-Edge Sword of Online Media

While the Internet has democratized access to medical information, with estimates that 70% of adults in the United States have utilized online health information, especially about cancer and its treatment, widespread use of the Internet has also resulted in the rise of health misinformation and disinformation.3 Although both misinformation and disinformation refer to types of wrong or false information, there are distinctions between the two. Health misinformation is defined as any health-related claim of fact that is false based on current scientific consensus, while disinformation is defined as a coordinated or deliberate effort to circulate misinformation knowingly to gain power, money, or reputation.3 Both can spread rapidly online.

A review of 50 of the most popular social media articles on each of the four most common cancers, including breast, prostate, colorectal, and lung, posted on Facebook, Reddit, Twitter, or Pinterest between January 2018 and December 2019, found that about one-third of the articles contained misinformation, and nearly 77% contained harmful information that could lead to treatment delays, toxicity of recommended procedures, and/or adverse interactions with the current standard of care.3

Social media platforms continue to pose new challenges for both consumers seeking health information and oncology professionals looking to educate their patients and help them discriminate between accurate cancer information and misinformation and disinformation. They can also present new opportunities for patients to become better informed about their cancer and treatment options.

To ensure that patients can find trusted, expert information online, earlier this year, ASCO and the American Cancer Society (ACS) launched an initiative that allows both organizations to cross-share cancer prevention, screening, and survivorship resources on their patient and consumer education websites, ASCO’s Cancer.Net and ACS’

Kasisomayajula “Vish” Viswanath, PhD

Kasisomayajula “Vish” Viswanath, PhD

“I don’t think we can eliminate misinformation and disinformation from social media platforms, because that train has already left the station,” said Kasisomayajula “Vish” Viswanath, PhD, Lee Kum Kee Professor of Health Communication in the Department of Social and Behavioral Sciences at the Harvard T.H. Chan School of Public Health; and Faculty Director of the Health Communications Core of the Dana-Farber/Harvard Cancer Center. “What can we do? Brand name still matters and ASCO has credibility in providing evidence-based, accurate information to the public. My feeling is that organizations such as ASCO, the American Association for Cancer Research, American Medical Association, American Cancer Society, the National Cancer Institute, and other professional medical organizations should band together to counter online misinformation by developing guidelines, for example, on health-care screenings for cancer and other illnesses and standard-of-care recommendations, because these organizations have credibility with the public.

“While social media platforms will not be able to eliminate misinformation and disinformation completely, they have the power to reduce it considerably through their content-monitoring algorithms, so inaccurate information doesn’t get any prominence on their sites. This is controversial, but they can also vet the information, and kick people off their websites for posting false information.”

In an interview with The ASCO Post, Dr. ­Viswanath discussed how social media amplifies misinformation and disinformation about cancer and other diseases and helps create distrust in science.

Sowing Seeds of Doubt

Please talk about how social media accelerates misinformation and disinformation about cancer and hinders cancer communication?

The spread of misinformation and disinformation is not new, especially when it comes to cancer. For example, the tobacco industry has always been very successful in sowing seeds of doubt about the health risks of smoking and promoting active disinformation about the connection between smoking and the development of cancer.

What is different now? One, is the advent of social media and its ability to spread disinformation and misinformation rapidly across the United States and globally, allowing people to connect across time and geographical boundaries, and find others they have common ground with.

Second, there is no gatekeeping process in place to ferret out inaccurate information like there is in the peer review process to publish an academic article in a professional journal, in which reviewers look at the soundness of a study and its methodology, and if it is not correct, the article is rejected for publication.

But I can tell you the information posted on sites like Facebook is not being validated. It is this lack of gatekeeping, the absence of gatekeeping, that allows people to post anything they want.

Everybody now is an information producer and disseminator. People don’t need a professional writer to help them write an article and a platform like a newspaper to publish it. Now, they can write 280 characters on any subject and post it, and they become their own disseminator, which is leading to greater visibility of misinformation.

Then when this misinformation is picked up by a prominent politician or an influential person and then legitimate news organizations, it gives credence to the information, and other media publish it. This process is called spiral of amplification. One example is the disinformation and misinformation about the efficacy of hydroxychloroquine and ivermectin in the treatment of COVID-19. Before the pandemic, I had never heard of ivermectin, a drug used to treat certain parasitic roundworm and threadworm infections, but slowly it started being purported as a treatment for the coronavirus, and even the most careful news media had no choice but to cover these medications, so there is a reciprocity between online and offline news outlets, which is how problems of misinformation and disinformation are compounded.

Overcoming Political Polarization

Medical quackery has been around for decades, but it is so much easier now to spread information that isn’t true, for example, ivermectin to treat COVID-19. Why are people willing to take medicines that are unproven to be effective instead of taking medications for a disease that have been proven safe and effective?

In general, about 70% of parents got their children vaccinated against the coronavirus. The people who refused any vaccination either for themselves or for their children was small, about 10%. Having studied vaccine hesitancy, people who refuse vaccinations come from both the extreme right and extreme left of the political spectrum, including people who only eat organic food and don’t want to ingest anything that is artificial to people who are ideologically opposed to vaccines because they do not want their personal freedom and autonomy infringed upon.

The issue you are raising regarding the willingness of people to take unproven and alternative remedies is the result of increasing polarization in this country. I have to confess that I had not anticipated such strong resistance. I predicted that there would be some resistance to the vaccine similar to what we have seen with other types of immunization. But I did not predict that there would be members of a political party that would actively oppose the COVID-19 vaccine, and over time that opposition grew because of the political polarization in the country.

Rejecting Science

It appears that there is now a level of skepticism and rejection of science that we have not seen before.

I agree. But my feeling is that the problem is not solely due to online misinformation and disinformation. I’m sure it is contributing to the problem, but there is something else going on.

We have not gone through anything like the COVID-19 pandemic since the 1918 flu pandemic, and we have been asked to comply with many guidelines simultaneously to stay safe. For example, getting vaccinated, social distancing, and wearing a mask, all at the same time, which have caused a complete disruption in our lives.

I’m not saying that disinformation and misinformation are not contributing to science skepticism, but there are other factors involved.

Assessing the Pros and Cons of Online Media

How prevalent is social media in low- and middle-­income countries and what is their impact on cancer care?

In general, the penetration of social media is directly related to a country’s gross national product. Most people who are on the internet and social media sites are in high-income countries, whereas people with a limited access to the internet and social media are in low-income countries. But having said that, there is an increasing change where more and more people are going online and accessing social media platforms even in low-income countries, although it may still be limited to people who are well off.

In India, for example, only between 40% and 50% of people are on social media, but that amounts to 500 or 600 million people, so it’s not a trivial number. And the effect is both positive and negative.

Although users are able to collect health information on sites like WhatsApp and receive messages about free cancer screenings in a specific hospital, which are shared widely, they also receive messages saying tobacco doesn’t cause cancer.

So, social media is adding to the complexity of the information environment and causing problems, but we need data showing how sites are influencing cancer services through misinformation and disinformation.

What we do know is that among health-care professionals, social media has been somewhat helpful in connecting them and their patients to cancer care resources. But we have to wait and see what will happen over time to assess the positive or negative effect of social media on cancer care. 

DISCLOSURE: Dr. Viswanath reported no conflicts of interest.


1. Ault A: History Shows Americans Have Always Been Wary of Vaccines. Smithsonian Magazine, January 26, 2021. Available at Accessed May 4, 2022.

2. Burki T: The online anti-vaccine movement in the age of COVID-19. Lancet Digit Health 2:e504-e505, 2020.

3. Teplinsky E, Ponce SB, Drake EK, et al: Online medical misinformation in cancer: distinguishing fact from fiction. JCO Oncol Pract. March 31, 2022 (early release online).