Thursday, February 18, 2010

Gardasil pros and cons

Gardasil has been hailed as the first vaccine against cancer, protecting women against some of the strains of human papillomavirus. HPV can, in a tiny percentage of cases, cause cervical cancer. Gardasil also been reviled as oversold and potentially dangerous. Here’s what you need to know:

• Up to 80 percent of people will get HPV, a virus akin to the common cold, in their lifetime. There are more than 100 strains of HPV, multiple strains of which COULD cause cancer in limited circumstances.

• 95 percent of those infections are self-limiting—they’ll be beaten off by your immune system, leaving you immune to further infection with the same strain.

• Only if an infection becomes persistent could it cause pre-cancerous lesions.

Your behavior dramatically affects the chances of an infection becoming persistent.

If you smoke, you have up to a 2,700 percent greater chance of getting a persistent HPV infection. (Anthony Gunnell, M.A.Sc., Karolinska Institutet, Stockholm; November 2006, Cancer Epidemiology, Biomarkers & Prevention)

If you don’t eat vegetables and fruit regularly, you are 50 percent more likely to get a persistent HPV infection. (Rebecca L. Sedjo, MSPH, et al: University of Arizona, US; Cancer Epidemiology, Biomarkers & Prevention)

• If you have multiple sexual partners, you will exponentially increase your chances of getting a persistent HPV infection.

Oral birth control and having sex at a young age may increase HPV risks.

• Being uncircumcised or having an uncircumcised partner increases HPV risks.

Insufficient sleep on a regular basis, drug use—anything, in fact, that depresses your immune system—will increase your chances of getting a persistent HPV infection.

• With all that, if you get regular Pap smears, the chances of an infection progressing to pre-cancerous lesions and then cervical cancer are very small, and if it does, it is extremely curable when caught early. About 4000 women, some 60 percent of whom have not had smear tests, will die of cervical cancer in the US this year. It is twice as likely to affect Hispanic women and 50 percent more likely to affect African American women, probably because of economic factors. The number of cases drops by about 4 percent annually.

• Gardasil protects against the two strains of HPV, 16 and 18, that currently cause close to 70 percent of cervical cancer, plus two wart-causing strains. There are more than 100 strains of HPV. Merck’s research shows a small degree of cross-protection against strains not covered by the vaccine.

• Gardasil is a novel type of genetically engineered vaccine.

• Although ads imply that you will not get cervical cancer if you get Gardasil, Gardasil does not protect against many oncogenic strains of HPV. So far, Merck’s research has shown a rather meager 17-45 percent reduction in all cervical abnormalities in vaccinated girls. Recent figures of 89 percent reduction refer only to abnormalities and persistent infections caused by the four vaccine-type strains and do not include abnormalities caused by other strains.

• Although HPV16 and 18 caused the majority of invasive cervical cancer in a sample of women in New Mexico, the overall proportion attributable to HPV16 has dropped over 20 years, giving way to non-18 types. (C.M.Wheeler, PhD, University of New Mexico; Journal of the National Cancer Institute 2009).

• There is some concern that non-vaccine HPV types will fill the biological niche, an effect known as replacement disease. Merck does not think this likely, although it has happened with the vaccine Prevnar.

• The effect on natural immunity and duration of protection is currently unknown. Nor is the effect of new HPV infection in older adults when immunity has worn off.

• Merck’s research showed initially that Gardasil caused a 44.6 percent increase in the highest grade of pre-cancerous lesions in women who were already infected with vaccine-type HPV. Merck determined that the study was unbalanced and that those women also had high risk factors such as smoking. After ‘balancing’ the study, the combined figure for subgroup studies showed an enhanced risk of disease of 11.7 percent for females who had vaccine-type HPV at the start of the study.

• If you are already sexually active, get an HPV test prior to vaccination, particularly if you smoke or are otherwise high-risk.

• A neurologist has expressed concern about unusual immune response-mediated inflammation in the spine of a girl who died from an unusually rapid onset ALS-type disease and believes it may be associated with Gardasil.

• The FDA associates Gardasil with heightened risks of syncope and blood clots.

• Gardasil has also been associated anecdotally with Graves Disease, paralysis, Guillaine-BarrĂ© syndrome, seizures, chronic headache, and various autoimmune diseases although not at statistically extraordinary levels. Merck’s studies showed a slightly elevated risk of various types of arthritis. Incidence of autoimmune disease, which is triggered in susceptible people by environmental factors, is rising rapidly and an ever-increasing lifetime burden of vaccines and accompanying adjuvants may be a factor. This has not been proven, however. In trials of Gardasil, placebo vaccinations used an aluminum-containing adjuvant, something that could mask sideeffects.

• You should still get regular Pap tests, even if you have been inoculated with Gardasil.

It’s important to honestly assess your family medical history and lifestyle prior to getting the course of vaccinations. Read up on the facts. Gardasil may well be right for you, but it is not 100 percent effective or safe. Know its limitations—and yours.


Anonymous said...

How can a parent evaluate whether to have a daughter vaccinated at the age of 11-14 when the behaviors likely to result in a persistent HPV infection are unlikely to develop or be known until well into adulthood? In other words, while its helpful to know that smoking and multiple sexual partners and not eating fruits and vegetables dramatically increase the risk of persistent HPV infection (because there is still plenty of time to encourage other behaviors instead), it seems that the window of getting the vaccine is already closed by the time it could actually be beneficial?

Kristin Johns said...

Fair comment, and believe me, I've thought about it a lot. It's clear that if you're going to get the vaccine at all, best to do it prior to becoming sexually active.

However, everyone has to balance the risks and rewards of a particular vaccine for themselves--and unfortunately few doctors take the time and trouble to understand, let alone share, the full facts about any disease. Instead they just sell a 'one size fits all' approach.

What I've ended up doing is just talking very bluntly (probably a little TOO bluntly for their tastes!) with my daughters. The healthy behaviors that will protect them from persistent HPV infections (not 100 percent, I'm sure, but probably better than Gardasil alone, judging by current results) will also protect them from many far worse diseases. They've witnessed my BIL dying from cancer; they're not particularly keen on going through that themselves.

And you have to remeber: HPV isn't a sudden attack disease, like polio or meningitis. That makes a difference to me.

There aren't any perfect options. A child could end up drinking, drugging, smoking, living on fast food and being the town bike despite a parent's best efforts. In which case, darn, should have got the Gardasil shots. Except that cervical cancer is probably the least of their worries anyway.

However, I think our generation tends to treat our kids like morons with no self-control. In previous generations there were always a few reckless kids: now we seem to expect that all kids will be reckless. Teens will actually quote Time magazine articles saying that some part of their brain isn't yet developed (I've heard them) and so they can't possibly be expected to restrain themselves.

Pitiful. If they're smart enough to read the article, they're smart enough to eat some flipping spinach occasionally.

Anonymous said...

Thank you I agree with all of what you say. Of course my issue is that I have a 12 year old who eats very little in the way of fruits and vegetables - the only one of these behaviors that is currently a concern (as it is on any number of fronts...). She is very much against smoking so I don't see that as an issue and can't at the moment imagine that numerous sexual partners will be an issue - but as I said in my original post, I can't know what the future will bring in that respect. I have resisted her pediatrician's recommendations to get the vaccine for the past 3 annual checkups but found myself challenged by a doctor acquaintance who was astonished that I had any issue whatsoever with getting the hpv vaccine. So I've been trying to confirm that I'm not unnecessarily exposing her to something that she could avoid...

Kristin Johns said...

Your only defense is to educate yourself AND your daughter. A lot of what's written on the internet about Gardasil is extremely debatable at best. I'm not a doctor--and you should try to find a doctor who will take the time for a rational discussion. As I said, there is no perfect solution, so you have to find the one that seems most logical to you.

Fruits and veggies are important, so keep pushing them in various forms. As a baby my eldest would never eat broccoli and I served it up at every meal. Finally, figuring she'd not eat it anyway, I served up some yellowing, old broccoli and to my horror she ate it--never had a problem again. Weird. I found a divine peanut sauce in Vegetarian Times that makes broccoli etc. pretty palatable.

Good luck. Just wait til she gets a car....

Anonymous said...

Thank you for follow-up comment. And I understand that you are not a doctor, but I really like your approach and feel that you have been very balanced on this blog - something very difficult to find on the internet btw. Maybe I should speak to an oncologist about cervical cancer or even my gynecologist to understand what happens after pap tests currently to understand what the vaccine is trying to avoid...

Rleif said...

Unfortunately, the data on colposcopy is poor. I have heard the presentation. The comparable Pap tests were NOT performed according to first world standards. You are endangering our children. Vaccines are the method of choice to eradicate viral pathogens.