Gardasil on Trial: Did Merck Mislead the Public on Cervical Cancer Prevention?

Top expert delivers a damning report accusing Merck of misleading the public about Gardasil’s ability to prevent cervical cancer.

With the landmark trial against Merck adjourned until September 2025, new evidence suggests the vaccine manufacturer may have deliberately misrepresented the necessity of mass HPV vaccination.

This revelation comes from an expert report by Dr Sin Hang Lee, a pathologist renowned for his expertise in molecular diagnostics. His findings raise serious concerns about Gardasil’s efficacy and the motives behind its aggressive marketing.

Dr Sin Hang Lee, director of Milford Molecular Diagnostics, Connecticut

Does Gardasil Prevent Cervical Cancer?

Since its introduction in 2006, Gardasil has been marketed as a breakthrough in the fight against cervical cancer.

Yet, as Dr Lee bluntly states in his report, “There is no conclusive evidence that Gardasil has prevented a single case of cervical cancer in the past 18 years.”

No randomised controlled trial (RCT)—the gold standard for assessing efficacy—has ever demonstrated that Gardasil prevents cervical cancer.

Instead, Merck relied on surrogate markers of pre-cancers, such as cervical intraepithelial neoplasia (CIN2/3) to claim effectiveness. This is a significantly lower evidentiary bar that was used to fast-track FDA approval.

The problem with this approach is well-documented. Many CIN2/3 lesions resolve naturally.

A Dutch study, for instance, tracked 114 women with CIN2/3 found that nearly two-thirds of cases regressed without intervention. Only one developed adenocarcinoma in situ (pre-cancer) and none progressed to cervical cancer.

Moreover, those lesions that don’t resolve naturally typically take years to progress, and they are usually detected through routine screening.

If CIN2/3 is an unreliable proxy for cancer, how can it serve as valid proof of Gardasil’s claimed efficacy at preventing cancer?

Are HPV Strains Merely Being Replaced?

Another major concern is “type replacement”—the possibility that suppressing certain HPV strains through vaccination leads to the rise of others.

For instance, a Finnish study found that while HPV strains 16 and 18 (targeted by the vaccine) decreased following vaccination, non-vaccine strains such as HPV 52 and 66 became more prevalent.

This raises an important question: While Gardasil may alter the landscape of HPV infections, does it actually reduce the overall risk of developing cervical cancer?

When Merck developed Gardasil 9 to target five additional HPV strains, a study involving 14,215 women found that those who received Gardasil 9 developed high-grade lesions at the same rate as those who received the original Gardasil (which only targeted four strains).

Despite the expanded coverage, the additional strains had no measurable impact on pre-cancers overall, adding to the uncertainty about whether these vaccines truly reduce cervical cancer incidence.

The Questionable Swedish and Scottish Studies

Two widely cited studies—from Sweden and Scotland—are often heralded as proof that Gardasil significantly reduces cervical cancer rates. However, Dr Lee highlights critical methodological flaws in his report.

• Swedish study

The Swedish study, published in the New England Journal of Medicine, compared cervical cancer rates between vaccinated and unvaccinated women.

However, Dr Lee points out that many participants (born between 1995 and 2007) were too young to develop cervical cancer during the study period (2006–2017).

Since cervical cancer takes decades to emerge, including these young women (ages 10–22)—who had zero cases—introduced a statistical bias that exaggerated the vaccine’s effectiveness.

Moreover, the study failed to account for the “healthy user effect,” where vaccinated individuals are more likely to engage in preventive health measures like regular screening, which independently reduces cancer risk.

As a result, attributing the decline in cancer cases solely to the vaccine is misleading.

• Scottish study

A 2024 Scottish observational study, published in the Journal of the National Cancer Institute, had similar methodological issues, and was met with sensationalist media headlines: “No cervical cancer cases in HPV-vaccinated women.”

However, Dr Lee argues this claim is deeply flawed. First, the women studied were simply too young for conclusions about long-term vaccine efficacy to be drawn.

Second, Scotland’s screening programme, which detects and treats precancerous lesions before they develop into cancer, changed its entry age in 2016 during the study period.

The age at which women were first invited for screening was raised from 20 to 25, meaning there was a 5-year gap in screening for younger women. As most cancers in women under 30 are diagnosed through screening, this change could explain any decline in cancer rates, rather than the vaccine itself.

And third, just like the Swedish study, the “healthy user effect” further confounds the results.

Despite being frequently cited as definitive proof of Gardasil’s effectiveness, these studies contain serious limitations that undermine their conclusions.

Cervical cancer screening saves lives

In developed nations, around 93% of initial HPV infections resolve without medical intervention. Cervical cancer is slow to develop, with an average onset age of 54, making long-term data essential for assessing Gardasil’s true impact.

What remains incontrovertible is the lifesaving role of cervical cancer screening.

Since the widespread adoption of Pap smears in the 1950s, cervical cancer incidence in the U.S. has plummeted—from 44 per 100,000 women in 1947 to just 8.8 per 100,000 by 1970.

This dramatic decline predates the introduction of HPV vaccination in 2006.

In Australia, deaths from cervical cancer fell significantly along with incidence following the introduction of the National Cervical Screening Programme, and remained steady despite mass HPV vaccination.

Source: https://www.hpvworld.com/articles/prevention-of-cervical-precancer-and-cancer/

Dr Nancy C. Lee, former Associate Director for Science at the CDC, testified before the U.S. Congress in 1999:

• “Cervical cancer is nearly 100 percent preventable.”

• “The most important risk factor for developing cervical cancer… is the failure to receive regular screening with a Pap smear.”

• “For a woman with CIN, her likelihood of survival is almost 100 percent with timely and appropriate treatment.”

Dr Nancy C. Lee, former Associate Director for Science at the CDC

Unlike cervical cancer, which is preventable through screening and treatable with early intervention, Dr Lee asserts the harms linked to Gardasil - such as autoimmune disorders and neurological complications - are unpredictable, difficult to treat, and often irreversible.

Did Merck Misrepresent Its Vaccine?

At the core of this legal battle is a critical question: Did Merck mislead the public about Gardasil’s true value?

Despite its widespread use, Gardasil’s long-term efficacy remains unproven, while growing evidence links the vaccine to serious harms, including autoimmune disorders and neurological complications.

For decades, cervical cancer rates have declined due to improved screening—not mass vaccination. Yet Merck has aggressively marketed Gardasil as essential for cancer prevention, even in countries where cervical cancer is already rare.

Dr Lee’s report suggests Merck selectively presented data to manufacture a false sense of necessity—one that collapses under scrutiny.

As the trial resumes in September, one question remains: Did Merck knowingly misrepresent Gardasil’s safety and efficacy, prioritising profit over public health?

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Additional reading:

EXCLUSIVE: Internal emails reveal Merck's negligence in Gardasil safety testing

Court Documents Reveal “Undisclosed” Adjuvant in Gardasil vaccine

FDA ignored residual DNA fragments in the Gardasil HPV vaccine

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