The independent source for health policy research, polling, and news.
Summary
This volume covers recent claims about COVID vaccine safety after a new study describes a rare condition it calls “post-vaccination syndrome” (PVS). It also investigates the false claim that ivermectin and other anti-parasitic medications can treat cancer and highlights the re-emergence of concerns online about the HPV vaccine, Gardasil, and its alleged mortality rate. Additionally, the Monitor explores the wellness industry’s promotion of unproven treatments as trust in health care declines and the accessibility of AI chatbots in providing health information across different languages.
Recent Developments
Small Study Sparks Fear About COVID Vaccine Safety as Some Call to Ban mRNA Vaccines
Concerns over COVID vaccine injury are growing as some call for the banning of mRNA vaccines in their state. Claims that long COVID is a vaccine-related injury have begun spreading online after Yale researchers shared preliminary findings from their study of a rare set of symptoms following COVID-19 vaccination that the authors call “post-vaccination syndrome” (PVS). The study, posted online on February 18 but not yet published in a scientific journal, describes the group of symptoms as fatigue, exercise intolerance, brain fog, tinnitus, and dizziness. PVS is not a disease recognized by the medical community, but a term created by the researchers to describe these reported symptoms. The study does not establish how common PVS symptoms are or whether vaccination causes them. Researchers compared blood samples from 42 vaccinated individuals reporting PVS with 22 vaccinated individuals who did not report adverse effects and found differences in immune profiles between the two groups. The study notes that they found similarities between PVS and long COVID, but the study’s senior authors explain that the findings are preliminary and require further research to determine the cause of PVS. The study gained attention online, with vaccine opponents misrepresenting the findings around long COVID. One popular post on X, published on February 19, featuring a screenshot of an article from The DisInformation Chronicle Substack, falsely claimed the study concluded that long COVID is a vaccine injury. The post gained traction after Elon Musk retweeted it, receiving approximately 7,800 reposts and 7,000 likes as of Feb. 25. Long COVID, which affects both vaccinated and unvaccinated people, is not the same as PVS and is not caused by vaccines. Studies have shown that vaccines, which are known to be safe and effective, can offer protection against long COVID.
While past KFF polls have found that exposure to COVID-19 vaccine misinformation is widespread in the U.S., a 2023 poll found that most of the public express confidence in the safety of vaccines, including six in ten (57%) adults who say they are at least “somewhat confident” in the safety of the COVID-19 vaccines, which lags slightly behind confidence in the RSV vaccine (65%) and the flu vaccine (74%).
False Belief That Cancer Is a Parasite Leads Some to Believe That Ivermectin Can Treat It
Some falsely believe that cancer is a parasite, leading to claims that antiparasitic drugs like ivermectin and fenbendazole can cure it. The claim existed in early 2023, but resurfaced on Facebook in December 2024. These claims exist across social media, with some accompanying their claims with statements questioning the safety and effectiveness of chemotherapy. The most popular posts on social media come from people who identify as medical doctors who share their patients’ testimonies on ivermectin effectiveness for cancer treatment. One X user, whose biography states that he is a radiologist and oncologist, shared screenshots of his own Substack article with these testimonies, receiving approximately 4,000 reposts, 11,000 likes, and 6,100 bookmarks in just 4 days.
Although some of these claims allege that this belief is supported by evidence, research shows that cancer arises from mutations in a person’s own cells, not from an external parasite. While some studies suggest ivermectin may slow tumor growth in research settings, it has not been extensively studied in humans, and no major health organizations have approved it, or other anti-parasitic medications, for cancer treatment.
Despite the lack of evidence, actor Mel Gibson’s appearance on the January 9th episode of The Joe Rogan Experience contributed to the continued spread of this claim. During the episode, which reached over 8 million views, Gibson stated that three of his friends had overcome stage four cancer using antiparasitic drugs, alongside other substances. Although unverified, the interview’s claims were widely circulated online by social media users and antiparasitic drug manufacturers who referred to ivermectin as the ‘miracle drug’ discussed by Joe Rogan and Mel Gibson.
Resurfaced Video Circulating Online Sparks Concerns About HPV Vaccine Safety
Gardasil ®9 is a vaccine that protects against 9 types of cancer-causing human papillomavirus (HPV) types, providing broad protection against a virus that is associated with cervical, anal, and throat cancers as well as ano-genital warts. The FDA approved it in 2014 after large-scale clinical trials found no increased risk of death and very high safety and effectiveness. Since widescale vaccination began, research has found steep declines in the incidence of cervical precancers among young women in the United States.
Discussions about HPV vaccine safety spiked online after an older video resurfaced of Health and Human Services (HHS) Secretary Robert F. Kennedy Jr. falsely stating that “the death rates in the Gardasil trials were 37 time the death rates for cervical cancer.” While some participants died during the trial, their deaths were attributed to unrelated causes. In fact, research before and after its approval shows that since HPV vaccination in the U.S. began, there have been significant reductions in cervical cancer death rates among U.S. women under 25.
A popular post on X, from an account with approximately 279,000 followers, shared the video of Kennedy on February 15 without any context on when or where Kennedy made the statement. In five days, the post received approximately 19,000 reposts, 52,000 likes, and 11,000 bookmarks. A political commentator known for sharing false claims about vaccines shared the post and amplified these false statements, with text that read, “This is the [vaccine] that injured me many moons ago. Grateful it happened though bc it woke me up to the Big Pharma scam and saved my children from vaccines.” This re-post received approximately 33,000 likes, 7,200 reposts, and 700 comments as of February 25.
Some of the 2,800 comments on the original post disputed or denounced this claim, but many commenters stated that they would not get HPV vaccines for themselves or their children due to unfounded concerns about the vaccines’ safety. Research shows that hundreds of millions of people have received HPV vaccines with no serious safety concerns reported.
HPV vaccines have faced controversy since the first HPV vaccine was approved in 2006, with some people making unfounded and false claims that HPV vaccines cause cancer and infertility and encourage risky sexual behavior. Doubts about the safety and effectiveness of COVID-19 vaccines have spurred waning confidence in vaccines across the board, which has contributed to declining HPV vaccination rates. These claims are resurfacing as a lawsuit against Gardasil’s manufacturer, Merck, gains media attention due to its connection to Kennedy. The case is currently paused until September, when it will reconvene with a new jury. This is likely to fuel the re-emergence of these claims close to September, as similar beliefs have historically gained traction when lawsuits against Merck receive media coverage.
Wellness Industry Promotes Unproven Treatments as Trust in Health Providers Declines
Recent KFF polling has found that public trust in government health agencies to make the right health recommendations has declined in the past two years, a continuation of a trend that began during the COVID-19 pandemic. While individual doctors remain one of the most trusted sources of health information among the public, trust in doctors has also declined moderately since 2023. Amid declining trust in many traditional sources of health information, some patients are turning to search engines and social media for health information. These platforms, however, often feature ads and posts promoting unproven treatments and wellness products that are misleadingly marketed as healthier alternatives. Wellness influencers position themselves as filling an information gap for those who feel unheard or dismissed by healthcare professionals. They sometimes package their messages into a desirable lifestyle and often play into cultural biases and preferences for natural health solutions. Some also spread false claims about FDA-approved treatments, such as vaccines, to promote their products or services as alternatives. While some pro-science content creators and health professionals share information on these platforms to counter false or misleading claims from the wellness industry, distinguishing credible information from false claims remains a challenge for many individuals. A 2024 KFF survey found that most of the public (67%) report they are “not at all” or “not too confident” the health information and advice they come across on social media is accurate, and four in ten (42%) are not confident in their own ability to tell the difference between what is true versus what is false when it comes to information on social media.
AI & Emerging Technology
Gaps in AI Chatbots’ Accuracy and Accessibility for Health Information Across Languages
KFF polling from 2023 found that one in six adults say they use AI chatbots for health information and advice at least once a month, but studies of AI models have found that gaps remain in delivering accurate and accessible health information across multiple languages. A study evaluating seven publicly available large language models’ (LLMs) ability to respond to cancer-related questions found that while English responses contained no clinically significant inaccuracies, non-English responses exhibited some errors. The study also identified concerns about reference quality, readability, and referral practices across both English and non-English languages, but they varied in extent. For example, English responses frequently exceeded an eighth-grade reading level, making them potentially difficult for the general public to understand. Many non-English responses were also complex, suggesting readability challenges across multiple languages. Additionally, similar to observations shared in the Monitor in August 2024, the study found variability in the inclusion of healthcare professional referrals.
Support for the Health Information and Trust initiative is provided by the Robert Wood Johnson Foundation (RWJF). The views expressed do not necessarily reflect the views of RWJF and KFF maintains full editorial control over all of its policy analysis, polling, and journalism activities. The Public Good Projects (PGP) provides media monitoring data KFF uses in producing the Monitor.