Misleading: Vaccine Adverse Event Reporting System (VAERS) data alone cannot confirm a causal relationship between vaccines and serious adverse events. Simply because an adverse event occurred after vaccination doesn’t mean that the vaccination was the cause.
FULL CLAIM: “Gates-Funded Plan to Vaccinate 86 Million Girls Against HPV Will ‘Unleash Mass Casualty Event,’ Critic Says”; there is “no single study that shows Gardasil can prevent cervical cancer”
An article published by Children’s Health Defense on 7 November 2023 claimed that a campaign for human papillomavirus (HPV) vaccination in low- and middle-income countries will result in a “mass casualty event” due to serious side effects caused by the vaccine. Purported side effects of the HPV vaccine include autoimmune and neurological disorders such as myalgic encephalomyelitis/chronic fatigue syndrome, fibromyalgia, and postural orthostatic tachycardia syndrome (POTS).
Children’s Health Defense (CHD) is an anti-vaccination nonprofit activist group led by Robert F. Kennedy, Jr., who is currently running as a candidate in the U.S. 2024 presidential election. We have previously reviewed numerous claims made by CHD that were inaccurate or misleading. CHD was also banned from Facebook and Instagram in 2022 for spreading misinformation about COVID-19.
Prior to the ban, a study evaluating vaccine-related advertising found that more than half of paid advertising sharing anti-vaccination content on Facebook stemmed from two buyers, including World Mercury Project, which was rebranded as Children’s Health Defense in 2018.
Cohort studies have found HPV vaccines are effective at preventing cervical cancer
Human papillomavirus (HPV) is a viral infection spread through skin-to-skin contact. It is the most common sexually transmitted infection in the U.S. There are more than 200 distinct types of HPV infections; some show no signs or symptoms and many clear from the body within one to two years without treatment. However, high-risk strains of HPV can cause genital warts and cancers, including cervical, oropharyngeal (back of the throat), anal, penile, vulvar, and vaginal cancers.
There are three HPV vaccines approved for use globally: Gardasil (quadrivalent), Gardasil 9 (nonavalent), and Ceravix (bivalent). Each vaccine prevents infection from the HPV types that cause genital warts and cancers.
The article’s claim that there is not “a single study that shows Gardasil can prevent cervical cancer” is false. It is true that cervical cancer takes many years to develop, which made it difficult to measure the immediate efficacy of HPV vaccines.
But now that it has been more than a decade since the HPV vaccine was approved in the U.S., Europe, and parts of Asia, recent years have ushered in positive results from cohort studies published in peer-reviewed journals including the New England Journal of Medicine, Journal of the American Medical Association (JAMA), Cancer Epidemiology Biomarkers & Prevention, and Journal of the National Cancer Institute. All these studies found that HPV vaccination is associated with a reduced risk of cervical cancer[2-5].
VAERS data alone cannot confirm causal relationships between vaccines and adverse events
The Vaccine Adverse Event Reporting System (VAERS) was established in the U.S. in 1990 to monitor potential health issues that arise after vaccination. It allows anyone to report adverse events after vaccination and to view such reports in a publicly searchable database. One of VAERS’ goals is to detect patterns of adverse outcomes after vaccination, such as a cluster of adverse events associated within a specific demographic, location, or batch/lot of vaccines.
Because VAERS relies heavily on self-reporting, it is prone to errors and duplications within its records. It is an imperfect database, as is the case with most forms of self-reported data. Still, identifying patterns among adverse outcomes can help researchers determine how to follow up regarding potential risk factors or other safety concerns related to vaccines.
VAERS data is commonly used to spread misinformation about vaccine safety and efficacy. Even before COVID-19 vaccines were developed, citing VAERS data as evidence of vaccine harm was a typical tactic employed by individuals and groups opposed to childhood vaccination. This trend continued with the introduction of the COVID-19 vaccine, with social media posts repeatedly using VAERS data in an attempt to prove that the COVID-19 vaccine caused serious medical problems.
The article claimed that HPV vaccination will result in a “mass casualty event” due to a “Severe Adverse Event rate” of 6.5%—in other words, that 65,000 serious adverse events will occur for every one million individuals vaccinated. The full quote from James Lyons-Weiler, who has spread health misinformation in the past, suggests that this figure originates from a study published in the journal JAMA in 2009 on serious adverse events reported to VAERS between 2006 and 2009.
VAERS data alone cannot confirm an association between vaccines and adverse events, which the authors of the JAMA article noted in their study’s limitations. While a serious adverse event like death or permanent disability may be reported to VAERS after receiving a dose of an HPV vaccine, it doesn’t mean that the vaccine caused that adverse event. In order to establish a causal relationship between a vaccine and an adverse event, many more factors need to be considered, which we covered in an earlier Insight article.
Even before the HPV vaccine was introduced, autoimmune diseases and neurological disorders were already occurring in people. Therefore, in assessing causality, one of the key components is in determining whether the incidence of an adverse event following vaccination is significantly higher than the baseline rate of that event in the population.
Evidence doesn’t support a causal association between HPV vaccination and neurological or autoimmune disorders
The article claimed that side effects of HPV vaccination involve neurological and autoimmune disorders, including chronic fatigue syndrome, fibromyalgia, and postural orthostatic tachycardia syndrome (POTS), but scientific evidence doesn’t support these conclusions.
A study evaluating reports of adverse events over an 11-year period in Australia found that adverse events including POTS, anaphylaxis, Guillain-Barré syndrome, complex regional pain syndrome (CRPS), and venous thromboembolism were reported at low rates and not associated with HPV vaccination. The study determined that fainting was the only notable side effect associated with HPV vaccination. Fainting is a reaction that can occur after many medical procedures—including vaccinations—usually triggered by pain or anxiety. It is generally harmless and doesn’t necessarily indicate a safety issue.
A study in the United Kingdom “found no evidence of an increased risk of Guillain–Barré syndrome [a neurological disorder] following HPV vaccination”.
Another study reviewing VAERS data from 2006 to 2015 found that POTS was rarely reported following bivalent, quadrivalent, or nonavalent HPV vaccination, at a rate that didn’t suggest any safety concerns.
A large cohort study of vaccine recipients in Sweden and Denmark didn’t find evidence for an association between the quadrivalent HPV vaccine and autoimmune or neurological illnesses.
In 2015, the European Medicines Agency (EMA) determined that there is not sufficient evidence to support a causal relationship between HPV vaccines and CRPS or POTS. Because symptoms of CRPS and POTS overlap with symptoms of chronic fatigue syndrome, the EMA report likewise determined that there is no evidence for a causal relationship between HPV vaccination and chronic fatigue syndrome. Credibility of sources cited by Children’s Health Defense
The article cited data published in Science, Public Health Policy & The Law to back up its claims about the dangers of HPV vaccination. However, the credibility of this journal is questionable. For starters, its Editorial Board doesn’t disclose any conflicts of interest, even though Mary Holland, one of the Editorial Board members, is the president of Children’s Health Defense. And James Lyons-Weiler, the Editor-in-Chief, is known for spreading health misinformation, especially about COVID-19 and the COVID-19 vaccine.
Cervical cancer is the fourth most common cancer in females worldwide. It was once one of the leading causes of death among women in the U.S. and remains responsible for hundreds of thousands of deaths annually in low-and middle-income countries. While no vaccine is 100% effective nor free from the risk of adverse events, evidence shows that the benefit of HPV vaccines in reducing cervical cancer outweighs the risks, contrary to Children’s Health Defense’s claims. Combining vaccination with regular cervical cancer screenings can reduce the incidence of cervical cancer.
[The following comments come from the evaluation of a related claim]
Jack Cuzick, John Snow Professor of Epidemiology, Wolfson Institute, Queen Mary University of London:
This is not a defensible set of statements. There have been millions of girls vaccinated and nothing other than vaccine site reactions have been established despite widespread careful review[11-13].
Kevin Ault, Professor, University of Kansas School of Medicine:
According to multiple well-done studies, the human papillomavirus (HPV) vaccine is not associated with autoimmune or neurological diseases. A large Scandinavian study of approximately 1,000,000 adolescent females looked at 29 different autoimmune and neurological conditions and “found no evidence supporting associations between exposure to […] vaccine and autoimmune, neurological, and venous thromboembolic adverse events.” Another large meta-analysis of 2,500,000 subjects in 109 studies found “no consistent evidence of an increased risk” of autoimmune and neurological diseases. It is inaccurate to state that this vaccine is associated with chronic health problems.
- 1 – Jamison et al. (2020). Vaccine-Related Advertising in the Facebook Ad Archive. Vaccine.
- 2 – Lei et al. (2020). HPV Vaccination and the Risk of Invasive Cervical Cancer. The New England Journal of Medicine.
- 3 – Tabibi et al. (2021). Human Papillomavirus Vaccination and Trends in Cervical Cancer Incidence and Mortality in the US. JAMA Pediatrics.
- 4 – Mix et al. (2021). Assessing Impact of HPV Vaccination on Cervical Cancer Incidence among Women Aged 15–29 Years in the United States, 1999–2017: An Ecologic Study. Cancer Epidemiology, Biomarkers & Prevention.
- 5 – Dehlendorff et al. (2020). Real-World Effectiveness of Human Papillomavirus Vaccination Against Vulvovaginal High-Grade Precancerous Lesions and Cancers. Journal of the National Cancer Institute.
- 6 – Slade et al. (2009). Postlicensure Safety Surveillance for Quadrivalent Human Papillomavirus Recombinant Vaccine. JAMA.
- 7 – Phillips et al. (2020). Adverse events following HPV vaccination: 11 years of surveillance in Australia. Vaccine.
- 8 – Andrews et al. (2017) No increased risk of Guillain-Barré syndrome after human papilloma virus vaccine: A self-controlled case-series study in England. Vaccine.
- 9 – Arana et al. (2017). Reports of Postural Orthostatic Tachycardia Syndrome After Human Papillomavirus Vaccination in the Vaccine Adverse Event Reporting System. Journal of Adolescent Health.
- 10 – Arnheim-Dahlström et al. (2013). Autoimmune, neurological, and venous thromboembolic adverse events after immunisation of adolescent girls with quadrivalent human papillomavirus vaccine in Denmark and Sweden: cohort study. BMJ.
- 11 – Vichnin et al. (2015) An Overview of Quadrivalent Human Papillomavirus Vaccine Safety: 2006 to 2015. The Pediatric Infectious Disease Journal.
- 12 – Stillo et al. (2015) Safety of human papillomavirus vaccines: a review. Expert Opinion on Drug Safety.
- 13 – Castle and Maza. (2016) Prophylactic HPV vaccination: past, present, and future. Epidemiology and Infection.