[Question #4492] HPV questions

29 months ago

I am 31 year old male, was in a monogamous sexual relationship that lasted 3 years and ended in 2015 (since then I didn't have any sexual partners). She was my first sexual partner, and she had several partners before me. I've been thinking about getting a HPV vaccine and researching about the efficacy of the vaccine in males as I've tried to determine to get the vaccine or not, but I've stumbled on some info and I could use your help with interpreting it. So here are my questions:

 

1. In this reasearch (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3495065/) about the efficacy of the vaccine, it says that efficacy with respect to persistent infection with HPV-6, 11, 16, or 18 and detection of related DNA at any time was 85.6%  and 44.7%, respectively. I don't know if I am interpreting the results right, but doesn't that mean that is still possible to get infected and to pass on the virus to someone else, if we are not in that '44.7% group of people' in which HPV DNA wasn't detected at all? I've often read here that for all practical purposes, the vaccine is 100% efficient in preventing HPV infections with the strains it covers, so i find this info somewhat conflicting. How this vaccine actually works? If I get vaccinated, does that mean i cannot get infected at all with those particular strains of HPV (the virus cannot get hold in my body, ergo cannot reproduce and infect others), or it means that I still can get infected, but the vaccine only helps my body to get rid of the virus more quickly and easily? What with that time period between getting infected and my body getting rid of the virus, will I be infectious to others during that time or the vaccine will help with keeping the virus count sufficiently low so I won't be infectious?

 

2. Is HPV more likely to be found on cervix than on the outside parts of vagina, like clitoris, labia etc? Is the cervix the main target/source of the infection, and then the virus gets spread around the vagina via penetrative sex? Is the amount of virus found on those other places equally infectious as it is on cervix?

 

3. If i get vaccinated, consistently use condoms for penetrative vaginal sex, but practice unprotected oral sex (giving and recieving) and unprotected genital rubbing with casual sex partners, would those practices be considered safe when it comes to HPV? Would the vaccination, plus the fact that oral sex and genital rubbing are not efficient ways of HPV transmission amount to low chance for getting the HPV and passing it on? How safe genital rubbing actually is when it comes to HPV?

H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
29 months ago
Welcome to the forum and thanks for your confidence in our services. I'll start with my core advice to all lpersons concerned about HPV. Catching and having genital HPV is a normal, expected, unavoidable aspect of human sexuality. Almost everybody is infected, most of us probalby several times. There are 100+ sexually transmitted HPV types. At any point in time, 20-50% of people age 18-35 have detectable HPV DNA in the genital/anal area (and recent research suggests that this also may apply to people in their 50s and 60s. The HPV vaccine prevents infection with 9 HPV types that collectively account for 90% of HPV related cancers and 85-90% of genital warts. 

1) The study you cite is one of many well respected investigations of HPV vaccine efficacy. I haven't re-read it in detail, but I'm pretty sure you are misunderstanding the main outcomes. All studies have shown 100% efficacy in preventing infection with the types covered in the vaccine they received. (Earlier versions of the vaccine covered 4 rather than 9 types.) Two kinds of apparent exceptions are common:  1) people who unknowingly had recently been infected with one of the vaccine types (there is no vaccine effectiveness after exposure has occurred); for example, an apparently new HPV 6 infection comes to light despite being vaccinated against it, but that infection in fact had been acquired before immunization. 2) Because warts or other abnormalities, such as pre-cancerous findigns on pap smear, sometimes result from non-vaccine covered types, vaccination does not prevent all such outcomes.

To answer your specific doubts:  Except in kids vaccinated before they ever have sex, most vaccinated persons have already experienced infection with one or more types included in the vaccine. The vaccine has no effect on those types. For example, if already infected with, say, HPV 11, 16, and 18 (three of the most common types) before immunization, that person could still get future geniital warts or cancer and transmit the virus to his or her sex partners. But that person is totally immune to ever getting (and therefore transmitting) any vaccine types not present before vaccination.

2) All those sites can be infected and I am not aware of documented differences between them. Contact with any of those anatomic areas can transmit HPV. The exact mechanisms by which HPV acquired at, say, the cervix then shows up on the vulva or around the anus isn't known. 

3) As described, such practices would reduce the chance of new HPV ifnection (with types not covered by the vaccine) but would not entirely prevent them. There is no practial way to be sexually active without acquiring HPV. (Even regular condom users have little reduction in eventual risk of HPV.)

A corollary to all this is that people should view vaccination as very good protection (roughly 90%) against important health outcomes (warts, cancer), but not for the purpose of preventing all HPV or preventing transmission to partners.

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

HHH, MD
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29 months ago
Thank you doctor for the answers, they were very helpful, but I could use a little bit more of clarification on some matters, if that's all right.

I wanted to include more informations in my original question, but I've tried to keep it as short as possible because of the character/word limit. The research info I found conflicting was the fact that in per-protocol population (1390 subjects who received all 3 vaccinations, were seronegative on day 1 and PCR-negative for specimens from day 1 through month 7 for the relevant vaccine HPV types and did not have any protocol violations) there was still 15 cases of persistent infections (caused by strains covered by the vaccine), and 136 cases of HPV 6/11/16/18-related DNA detections.

On the other hand, I've read on various other places that DNA detection of HPV doesn't necessarily mean infection or that the virus is present in sufficient numbers to be infectious, and this research doesn't tell anything about whether those 136 cases of DNA detections are infections or not, nor it goes into details about the effect the vaccine might have on the amount of the virus present in those samples where HPV DNA was detected. If detection of the virus doesn't necessarily mean we are infected or infectious, how do the researchers differentiate between the two? Can they differentiate at all?

My main reason of thinking about getting vaccinated is not because I am worried about my own health, I understand that possible bad outcomes for males are rare, it was more because I wanted to lower the chances of getting the virus and spreading it further. Would my potential sexual partners, casual or not, benefit at all from me getting vaccinated, and how much?

H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
29 months ago
I haven't recently read the paper in the detail you apparently have, but I have difficulty believing that almost 10% of people in the study really acquired the HPV types listed after they received 3 doses of vaccine. Part of the problem may lie in the fact that the blood tests for HPV probably detect only 70-80% of infections, i.e. negative antibody at the start of vaccination does not prove absence of those HPV types.

It is also true that we do not know whether positve HPV DNA implies a transmissible infection. The conservative approach is to assume that such persons are infectious for their partners, but we don't really know how frequently HPV is transmitted in this circumstance. And you correctly understand that the meaning of DNA, in terms of whetehr an HPV infection is active or not (i.e. actively replicating and hence transmissible virus).

Your motivations for vaccination are honorable, and I did not mean to imply there is no benefit in reducing transmission potential to partners. It's just not the main or usually the only consideration. Whether your partners will actually beneift, however, cannot be certain. They will not be protected from any HPV type which you have already had, which isn't possible to know reliably; so their protection will depend on your own sexual practices and behaviors (i.e. the likelihood you will acquire new infections) going forward. And also, of course, on whehter your partners have previously been infected or not, with HPV type(s) you may have; and whether they themselves have been vaccinated against HPV. If you and/or your partners are over 25-30 years old, the statistics are that your being vaccinated will have little effect on risk to your partners.
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29 months ago
Thank you doctor! Ok, so let me summarize the info I've got to see if I understood it all correctly;

1. In the case I do get vaccinated, I will be protected by those strains covered by the vaccine (under the assumption I didn't acquire them before the vaccination), I won't be able to get infected by them and pass them on, and only potential 'danger' will come from those strains not covered by the vaccine that cause 10% of cancers, is that right? Let's say I stumble on a potential sex partner with known active HPV16 infection, would it still be recommended to use condoms for vaginal sex on account of HPV16, or since I would be vaccinated the condoms wouldn't be necessary?

2. Regarding those strains that are not covered by the vaccine, is their prevalence in the population the same as with those strains covered by the vaccine, meaning it's equally likely to come in contact with someone infected with them as it is with let's say HPV16 or 18, or they are simply not so spread out in population, so that's why they weren't included in the vaccine?

3. If HPV viruses need to be rubbed into the skin to infect the tissue, taking advantage of the micro abrasions that are created that way, would using some kind of lubricant in the case of genital rubbing help with lowering the chance of infection?

4. The last and probably the most important question is, what would be the right attitude towards HPV? I would be very grateful if you could help me gain some healthy perspective on it. Ever since I've found out about HPV, only thing I think about is how much of a danger I could represent to potential sexual partners, especially if they are virgins, and that I might do them more harm than good by sleeping with them. Is HPV dangerous enough so that it should come into consideration when choosing sex partners and when deciding what kind of sex life we're gonna practice (i.e lifelong monogamy or non-monogamous life style)? I mean, I want to do the responsible thing and do everything I can on my side to protect the others, but I don't wont to go overboard with it and become a hostage of it. I see many other people and friends around me, they are not even aware of HPV, they lead their sex lives never giving HPV a thought, and ever since I've found about it I feel burdened with the knowledge about it. Should I just get vaccinated, consistently use condoms and then just forget about it?
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
29 months ago
1) I agree, except that there are other important reasons to use condoms for sex with new or casual partners. Of all STDs preventable with condoms, HPV is the least preventable:  regular condom users catch genital HPV just as often as non users. And several other STDs are more dangerous than HPV16.

2) Among the roughly 100 HPV types not covered by the vaccine, some are very rare. Others may be present in 10-20% of potential partners. Taken as a group with wide diversity, I would guess the non-vaccine types comprise about half of all infections in sexually active people. This is only an educated guess, however.

3) Good question. It would make sense that excellent lubrication might reduce the risk of transmission of HPV, and perhaps also other STDs transmitted primarily skin to skin, like herpes. But there are no data at all. If it makes any difference, it's probably small.

4) I answered exactly this question in the opening paragraph reply above. Beyond that statement, this is a complex issue and I would encourage you to exposure the ample informattion available on many websites. I suggest starting with the sponsor of this forum, the American Sexual Health Association (http://www.ashasexualhealth.org/stdsstis/hpv/) and the Centers for Disease Control and Prevention (www.cdc.gov/std). For the most part, the "responsible thing" is to be vaccinated; inform partners about current but not past known HPV infection; and otherwise stop worrying about it.

That concludes this thread. I hope the discussion has been helpful.
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