[Question #7615] Gardasil 9 Vaccine

3 months ago
I am wanting to get the Gardasil 9 vaccine.  I am 34yrs old and after discussing with my Dr, he recommended me to get the vaccine.  Given my history and the benefits he felt I should get it.

I have never had an abnormal pap test or any genital warts.  I have had few partners and have not had sex in 7yrs.  During this 7yr period, I have self examined myself regularly and have had no genital warts.  I have never had an abnormal pap test and get them every 3yrs since 20yrs old. Also had a normal exam from a gynaecologist 2yrs ago.

I have a few questions about the vaccine before I get it:

1. Can Gardasil 9 cause an HPV infection? If not- can you please explain how the vaccine works and why this is not possible?

2. If I had a previous infection of HPV that causes genital warts, but had no symptoms. Could the vaccine trigger or activate the existing virus in my body and cause an outbreak of genital warts?  If not- how is this not possible?

3.  If I had a previous infection of HPV that causes cervical cancer, but never had an abnormal pap test or symptoms.  Could the vaccine trigger or activate the existing virus in my body and cause symptoms or an abnormal pap test? If not- how is this not possible?  

4.  Can Gardasil 9 cause any serious side effects? Can it lead to a serious disease or fertility issues?

5. How effective is the vaccine in preventing HPV infections and how long does the immunity last?

I know these questions seem silly and I have anxiety regarding these infections.  The reassurance from the experts help me a lot and would make me feel comfortable about getting the vaccine.

Thank you!
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
3 months ago
Welcome back to the forum.

I reviewed our previous discussion about HPV a little over two years ago. Before getting to your questions, I have to wonder about the decision to consider HPV immunization at this time. Not being sexually active for several years, you're obviously not currently at risk for a new infection -- unless maybe you're anticipating a new relationship or (re)entering the dating scene? Now to your questions, but happy to discuss this aspect if you have any questions about it.

1) The vaccine does not contain HPV itself and cannot transmit infection. The active component is a protein that makes up the outer coating of the virus, but is manufactured biochemically -- not extracted from the virus itself. (This is the same idea as for most vaccines today. For example, the COVID vaccines so much in the news do not contain coronavirus and cannot transmit infection. Same for influenza vaccine.)

2,3) The HPV vaccine does not activate or reactivate existing infection and cannot induce warts in someone carrying a wart-causing HPV strain, nor cervical cancer or pre-cancerous cellular changes in someone carrying those HPV types. If anything, the opposite:  in theory it might reduce the chance a preceding infection.might reactivate. Why not? The biology here is quite complex -- for now I'll just leave it at that.

4) Virtually the only known side effect of Gardasil is the same as for any vaccine or other injection -- pain at the injection site. This is uncommon, and usually mild if it occurs at all. Dangerous side effects of HPV vaccine are not known to occur at all, or so rarely the risk can be ignored. In theory, anyone could have a severe allergic reaction to any vaccine, but I'm not aware this has ever actually occurred with Gardasil.

5) Gardasil is among the most effective vaccines ever developed. It protects 100% against 9 HPV types with which someone has not previously been infected (those that together cause 90% of gential warts and 90% of HPV-related cancers). Vaccine-induced immunity lasts at least 10 years and usually for life. As we discussed a couple years ago, you can safely assume you've had at least some of the HPV types covered by the vaccine -- it will provide no protection against future health problems from any such HPV infections you may have had in the past. But it will completely protect you from the rest of the 9 types covered by the vaccine.

I hope these comments are helpful. Let me know if anything isn't clear, or if you'd like to discus your decision to seek vaccination.