Wednesday, May 13, 2009

Health Authorities May Ditch Gardasil and Cervarix

Gardasil and its rival Cervarix cost governmental health programs, insurance companies and individuals billions. Most governments have approved vaccination programs on the assumption that if an HPV jab guards against the two viruses that cause 70 percent of cases of cervical cancer, then the vaccine will eliminate roughly 70 percent of new cancer cases.

Oops. Real-life study results don’t bear out that assumption at all, and now that Gardasil has been found in two placebo-controlled studies to reduce pre-cancerous cells by just a meager 17 to 45 percent, both Scotland and Germany are reconsidering their hugely expensive HPV vaccination programs.

13 leading scientists in Germany have said that the vaccine is leaving women vulnerable to other strains of the virus and that information about its effectiveness is misleading. The Robert Koch institute, which makes recommendations about publicly-funded vaccination programs in Germany, is reassessing Gardasil and expects to issue a report within about two weeks. As one expert said, "The results of the studies clearly contradict many overly optimistic pronouncements. Women are entitled to be adequately informed."

Women in the US are apparently not as entitled to be informed, as recent news reports about Gardasil have focused primarily on information that the vaccine has proved to be extremely effective against HPV strain 16 for up to 8.5 years—a statistic that now appears to be rather beside the point.

Senior public health experts in Scotland also warned that HPV vaccines might not be as effective as expected after reviewing the two large-scale studies of Gardasil. Although the competing vaccine Cervarix is administered by the National Health program in Scotland, Cervarix uses the same VLP-type vaccine along with a novel adjuvant to target the same cancer-causing viruses. Specific data about Cervarix’s efficacy is not currently available.

The randomized, placebo-controlled trials of Gardasil followed 17,622 women who underwent Pap testing at the start of the trials and then every 6 to 12 months. All the women showed no exposure to 14 common HPV types and had normal Pap smears to begin with. After 3.6 years abnormal cells were reduced by between 17 and 45 percent, depending on the type.

Colposcopies were reduced by 20 percent, cervical biopsies by 22 percent and surgery and other invasive treatments by 42 percent.

Results Unsurprising

A study published earlier this year in the Journal of the National Cancer Institute (JNCI) looked at both early and invasive cervical cancers from 1980 to 1999 in a New Mexico population. The study found that HPV types 16 and 18 had caused 66.3 percent (not 70 percent) of cervical cancers and, more worryingly, that type 16 was already being replaced by types other than 16 or 18 (the two strains covered by both Gardasil and Cervarix).

Although this replacement was taking place pre-Gardasil, experts have long theorized that one or more of the many other strains of HPV could fill the biological niche left by elimination of 16 and 18. This kind of ‘replacement disease’ has already been seen with the pneumococcal vaccine Prevnar. It’s unclear at this point whether replacement diseases have been the cause of Gardasil’s disappointing results as Merck did not release an analysis of the types of HPV found to have caused the abnormalities in the study subjects.

Merck is having better luck with Gardasil’s efficacy against genital warts. Gardasil, unlike Cervarix, also guards against two wart-causing strains and reports from Australia show that new diagnoses of genital wart infections have dropped by 48 percent.

Meanwhile, women who are weighing the pros and cons of the Gardasil vaccine, now have more complete information, even if—distressingly—the results of the two studies have received little publicity. Reports have associated convulsions, paralysis, epilepsy, numbness etc. with the vaccine, although as yet no causal link has been established.


Anonymous said...
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Anonymous said...

"Reduce precancerous cells by a meager 17 to 45 percent." Kristin, you don't understand the data. That being said, if I told you I could decrease breast or colon cancer risk by 17 to 45 percent with an injection, would you get it. If you say "no", you are being blinded by your ignorance. Jim M.D.

Kristin Johns said...

Could you explain the data to me, then? I'm always more than happy to correct errors.

The data came directly from Merck. I'm puzzled as to why health advisors in Germany and Scotland are reconsidering the vaccine on the basis of these studies if the studies actually translate to a very successful outcome.

Actually, no, I wouldn't get the shots you suggest because I'm at a very low risk anyway, for multiple reasons--so a 17-45 percent decrease would be relatively meaningless. If I had a very high risk, of course I would.

Equally, if I were a smoker, ate a really crappy diet, and slept around a lot I'd be far more likely to consider Gardasil. The big thing is to be informed and realistic.

But seriously, please do let me know how I should be interpreting the data.

Anonymous said...

I'd be interested to know if there's a different way to look at that data. I've been looking a Gardasil too and the results of the study make me wonder if it's worth risking side effects. Does Jim, MD, really know something different?

Anonymous said...

I hear there are some more HPV vaccines that cover more strains of HPV being develped. It might be worth waiting for those.

Debra J said...

I have a 10 year old so I am really studying this vaccine. Being so new it makes me nervous. Everyone I talk to says it is safe, but when I started researching it I'm not so sure. It seems like there are a lot of questions.