[Question #2948] What is the Efficacy of Gardasil After Sexual Activity?

41 months ago
I first became sexually active at 26 or 27. I have since been sexually active with <10 women, and have not always used a condom. No anal/anilingus. I have received the HPV vaccine at age 28 or 29 (completed the 3 series of injections).

Is there any benefit to me at all with the vaccine?
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
41 months ago
Welcome to the forum. Thanks for your question and your confidence in our services.

Congratulations for your diligence and responsible attitude to prevention of HPV (and presumably other STDs as well). However,, the available data don't allow a precise answer to this question. Most important, our past sexual history says nothing about your future risk of the need for vaccination, because it has no effect on existing infections. With a handful of sex partners, for sure you were infected with HPV, probably a few times. But the vaccine won't make any difference in your health risks from those (which are very low anyway).

That said, the vaccine is harmless and will prevent infection (with virtually 100% efficacy) with any of the 9 HPV types covered by the vaccine and with which you weren't previously infected. As for the cliche about chicken soup and any garden variety illness you can think of, "It can't hurt and might help".

I hope these comments are helpful. Let me know if anything isn't clear.

HHH, MD
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41 months ago
Hi, Dr. Handsfield.

Thank you for taking your time to respond to my question. I think I may have come across information in the past that said, even if I was exposed to HPV, Gardasil can still prevent, if you will, mouth/throat cancer. Is there some testing similar to IgG for HSV to identify which HPV type I may have? Do all 9 types potentially lead to cancer?

Thank you again.
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
41 months ago
That's true, but exposure doesn't mean infection, only that there has been contact with someone infected with HPV. In that event, immunization is 100% effective in preventing infection, if exposure is to one of the 9 HPV types covered by the vaccine. Once infected, the vaccine has no effect.

As yet there is no direct proof that the vaccine prevents throat cancer. However, it prevents infection with the type (HPV 16) that causes 90% of throat cancers caused by HPV, and almost certainly therefore is effective in preventing the disease. That said, although throat cancer due to HPV has been increasing in frequency in recent years, it remains an uncommon cancer and preventing it is not the main reason for HPV immunization.

There are over 100 sexually transmitted types of HPV. Many carry little or no cancer risk; if I correctly remember, 20-30 are considered high-risk (cancer-causing). The 9 HPV types prevented by Gardasil include two low risk types (HPV 6 and 11) which cause 90% of genital warts; and the 7 most common cancer-causing types. Those 7 account for around 90% of all genital, anal, and oral/throat cancers caused by HPV. So the vaccine is highly effective, but doesn't eliminate the chance of HPV or completely prevent HPV related cancers. But 90% protection is very good!

There is no generallyl available reliable testing to determine which HPV types a person might be carrying. And nothing to be done if positive for a high risk type anyway -- i.e. no strategies known to reduce the risk of eventual cancer or other symptoms in people who are infected, so really not much point in testing.

I cannot say you'll never develop an HPV related cancer. However, if you get cancer someday -- it causes around 40% of all deaths -- the chance is far higher that it will be one of the more common ones like prostate, colon, breast (for women), lymphoma, and all the others that have nothing to do with HPV. That's with or without HPV immunization, and regardless of sexual lifestyle.
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41 months ago
Thank you again, Dr. Handsfield for your very information responses.