Replying to some objections to Gardasil

I wrote this as a note on Facebook a couple of years ago as a response to some criticisms of the Gardasil HPV vaccine. Since Facebook is not searchable and it's hard to find old notes, I'm reposting it here in my blog. --Mike

Pamela, thanks for your extended response. You hit a lot of issues, which I will try to address. While it's important for any parent or teacher to understand these things, it's really crucial for you since it's in your area of professional responsibility.

As I see it, your main points are these:

1. Drugs are toxic to the body. "We all know there are chemicals in vaccines and it's hard to determine how they really affect us."
2. HPV does not lead to cancer in most women it infects. Only chronic infections lead to cancer and even then only in some cases.
3. You don't understand how researchers can determine how well the vaccine works.
4. The duration of protection is not adequate.
5. There is an unacceptable risk of serious reactions including death.
6. Political issues such as payment, rights of parents, and so on. This last is a matter of debate and political views rather than scientific fact, so I'm not going to address it.

First, let me say that it is not hard to find the facts on any of these issues. You can simply use Google Scholar to search for, say, "HPV vaccine efficacy" to come up with a good list of articles. Of course you can use PubMed (National Library of Medicine) for more flexibility, or just go to standard reference sources like emedicine.com, the CDC, the American Academy of Pediatrics, or your favorite university medical center site. There is no need to rely on non-professional sources for the factual questions (as opposed to policy or ethical ones). As a professional yourself, and one with the training to understand some of the science behind the issue, you ought to be familiar with the primary sources.

OK, issue (1) Are drugs and chemicals toxic? Everything is made of chemicals: our water, food, air, and our own bodies. So saying chemicals are dangerous is the same as saying everything is dangerous. As you doubtless learned in your pharmacology class, the issue is just how toxic things are and under what conditions. I don't stop eating plants because they contain small amounts of dangerous substances, nor do I avoid breathing knowing that oxygen is a quite toxic chemical (which is true). You say it is hard to determine how chemicals affect us, but that is the whole science of pharmacology and toxicology and we know the effects of many things very well, including the chemicals in HPV vaccine (basically a tiny amount of aluminum). See http://bit.ly/pLbqtb for more information. To make point (1) stand, you will have to come up with scientific evidence for the harmfulness of vaccine components.

Issue (2) You point out correctly that HPV does not lead to cancer in most women it infects. I'm not sure how you take this as an argument against the vaccine. Most car accidents don't kill people, but we still wear seat belts. The vaccine is highly effective against the kind of chronic infections that do cause cancer, and virtually all cervical cancers start with an HPV infection, so doesn't it make sense to immunize? Nearly all our vaccines are against illnesses that are usually relatively mild.

Issue (3) You don't understand how researchers determine efficacy? Then just read a couple of the research articles and see how they did it. I think the important little phrase in your quote is "generally available" test. Fortunately, researchers aren't limited to the routine tests, but have many of their own. Since they're dealing with a relatively small number of people, they can also spend a lot of time and money examining questions very carefully.

Studies have consistently shown that Gardasil prevents about 90% of infections and 90-100% of persistent infections and pre-cancerous lesions. With high levels of immunization, then, we would be preventing 90% of 4000 deaths per year, not to mention the genital warts and other problems far more common than cervical cancer deaths. See http://bit.ly/q22HQz, http://bit.ly/rhZUqd, http://1.usa.gov/nMpJ4k, http://bit.ly/quZsZ7, and http://bit.ly/mQ5hNk.

Is there any evidence for the non-efficacy of the vaccine, remembering that any opposing studies must meet or exceed the quality of these?

Issue (4) Duration of protection. This can only be determined as we go along and watch the immunized people over more years. We know already that the protection is at least 5-7 years, and perhaps in another 10 years we'll know that it's 15-17 years, or 10 years, or whatever. We don't stop giving tetanus immunizations because they have to be boosted every 10 years, do we, even though only about 45 people get tetanus each year in the whole USA and only 7 a year die? If a booster is needed, it can be given!

You mention in passing that the vaccine is not licensed for women over 27 years old, but I'm not sure why that is an issue. Naturally, as women get older more of them are already infected with HPV, so prevention becomes moot and the cost-benefit ratio of mass immunization shifts. In any case, though, a study published after the decision you quote did find that the vaccine was safe and effective in women 24-45 years old (http://bit.ly/mQ5hNk).

Should we immunize girls aged 9-10 if the vaccine only lasts 5-7 years? As a school nurse, I'm sure you know better than I! Given that some 30-35% of girls have had sexual intercourse by age 17 (National Health Statistics Reports, http://1.usa.gov/p6EjP4) it certainly seems like a good idea to me.

Issue (5) Safety. You say "CDC says 60+ women/girls have died after taking Gardasil (32 confirmed - jury still out on the others)." That is correct in the sense that 32 women are confirmed to have died somehow, sometime after being immunized, while the others could not even be traced, but none of the deaths were confirmed to be related to the vaccine. See the CDC report itself (http://1.usa.gov/oIvBfL).

Note that given existing mortality rates for all causes, one would expect at least 2300 of the 35 million immunized people to have died in any given month, immunized or not. For the sake of argument, though, let's suppose that 10% of those 32 confirmed deaths were actually vaccine related. That would make the risk one in one million.

Now if those same 35 million women were not immunized, during their lifetime about 238,000 of them would get cervical cancer and 71,000 would die from it. (It's not advanced research, just simple arithmetic given the lifetime risk of 0.68% and about 30% mortality, http://1.usa.gov/nZCkWX). Does it make sense to accept a risk of as high as 68 deaths (and almost certainly many fewer) to prevent 71,000 deaths?

Ah, you say, but not my daughter! She'll make moral choices, so even a one-in-a-million chance of dying is too much. First, can you be 99.9% sure of that? Because 99.9% certainty is what it will take to balance the risks. Do you think that only 1 in 1000 godly Christian (or other morally-determined) girls have premarital sex? Secondly, even if you're 100% sure about your daughter, are you 100% sure about her future husband? That's a different question, isn't it?

One final point. You say in passing disapproval that hepatitis B immunization is given to newborns. Do you understand why it's done that way? It's because some 80% of babies of mothers with active hepatitis B will become infected if not immunized very early, and about a quarter of those infected babies will die from liver disease. It's estimated that about 25,000 cases in children have been prevented since immunization was begun (http://1.usa.gov/nLBRAv) (Oh, and caring for children with chronic liver disease is VERY expensive!)

I hope that rather than rushing to refute these responses, you will take the time to look at the data with an open mind, evaluating not just one claim against another but the quality of evidence behind the competing claims.

References

• Reports of Health Concerns Following HPV Vaccination, CDC, http://bitly.com/pgjWBQ.
• HPV Vaccine Safety - Vaccine Safety, CDC, http://bitly.com/oIvBfL.
• Sustained efficacy up to 4-5 years of a bivalent L1 virus-like particle vaccine against human papillomavirus types 16 and 18: follow-up from a randomised control trial, Lancet, 2006, http://bit.ly/rhZUqd.
• Efficacy of the human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine in women aged 15-25 years with and without serological evidence of previous exposure to HPV-16/18. Int. J. Cancer, 2011, http://bitly.com/nMpJ4k.
• Prophylactic quadrivalent human papillomavirus (types 6, 11, 16, and 18) L1 virus-like particle vaccine in young women: a randomised double-blind placebo-controlled multicentre phase II efficacy trial. The Lancet Oncology, 2005, http://bitly.com/qWYm33.
• End-of-study safety, immunogenicity, and efficacy of quadrivalent HPV (types 6, 11, 16, 18) recombinant vaccine in adult women 24–45 years of age. British Journal of Cancer, 2011, http://bitly.com/mQ5hNk.
• Sexual Behavior, Sexual Attraction, and Sexual Identity in the United States. National Health Statistics Reports, 2011, http://bitly.com/p6EjP4.
• Human papillomavirus: science and technologies for the elimination of cervical cancer. Expert Opin Pharmacother 2011, http://bitly.com/rmUkIC.
• Cancer of the Cervix Uteri - SEER Stat Fact Sheets. National Cancer Institute, http://bitly.com/nZCkWX.
• A Comprehensive Immunization Strategy to Eliminate Transmission of Hepatitis B Virus Infection in the United States. CDC MMWR, 2005, http://bitly.com/nLBRAv.