HPV vaccine or not?
Comments (20)
Tuesday, September 25, 2007 | 12:01 PM ET
CBCNews.ca welcomed oncologist Dr. Joan Murphy on Friday, Sept. 28.
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- Download the audio of the interview (Runs 26:58)
Dr. Murphy, the chair of the Task Force on Cervical Cancer Prevention and Control for the Society of Gynecologic Oncologists of Canada, answered your questions about the HPV vaccine.
She is an oncologist and the head of gynecologic oncology at the University Health Network. She is also an associate professor in the department of obstetrics and gynecology at the University of Toronto.
To vaccinate or not. That’s the question facing many Canadian parents and daughters across the country.
The federal government's plan for a $300-million immunization campaign to prevent HPV or human papillomavirus, a virus linked to cervical cancer, is seen as controversial by some groups.
The National Advisory Committee on Immunization (NACI) said Canadian girls aged nine to 13 who have not yet become sexually active should be immunized with Gardasil, a vaccine that protects against four strains of HPV, which causes 70 per cent of cervical cancer and 90 per cent of genital warts.
But many parents are worried about side effects and what they perceive as a rush on the government's part to deliver a mass vaccination program.
An estimated 75 per cent of women will have at least one HPV infection in their lifetime. In 2006, there were an estimated 1,350 new cases of cervical cancer and 390 cervical cancer-related deaths in this country, making it the eleventh most common cancer diagnosis in Canadian women, according to the Canadian Cancer Society.
CBC stories:
- Immunize females aged 9 to 26 against HPV: advisory committee
- HPV vaccination plan should be halted, reviewed: researcher
- In depth: Gardasil
- In depth: Education, not vaccination, answer to HPV protection
This discussion is now Closed. View the questions.
Chat Questions (20)
Davide Gaeta
montreal
What evidence is there that the vaccine actually works, will you report the numerous cases of bad side effects that have occurred in the U.S.A
Editor's note: Re: side effects and testing results, please see answer to similar questions by other readers. You can also hear the interview in its entirety here. (Audio runs 26:58)
Host Bob Sudeyko:
Is it (Gardasil) 100 per cent effective? Will it truly prevent HPV?
Dr. Murphy:
First of all, Gardasil is actually effective against four different strains of the virus, only two of which we think are cancer-causing. It is almost 100 per cent effective against each of those strains.
C McKillop
Ottawa
How much testing of Gardasil has there been specifically on 13-year-old girls and what confidence can we actually have about there being no long-term negative effects for them?
Jen
Winnipeg
I do not like the idea that Merck & Co. pushed to get Gardasil released at the same time as they are trying to cover their losses from Vioxx, it seems coincidental, what do you think?
Dr. Murphy:
It’s very unfortunate the collision of events in time. I have nothing to do with Merck Frosst. I don’t know what happens internally. All I know is this vaccine is a good thing for women…the ministries of health, the professionals that have endorsed this are not burdened by the Vioxx death. There’s nothing in it for me, my colleagues or the ministries except the benefit of the population. I think it’s a very unfortunate coincidence. I don’t think there’s a direct relationship.
Susan
Victoria
Compared to other vaccines given routinely, how safe is the HPV vaccine?
Dr. Murphy:
The data to date which include something like seven million injections have been given in the U.S. since its approval…it is very safe. There is pain at the injection site; there can be some redness around at the injection site, and we keep hearing about people who have fainted…of the significant adverse reactions as they’re referred to, they don’t seem to be any more frequent in the vaccinated population than they are in non-vaccinated people of similar age.
Jennifer MacDonald
I am a 23 year old woman who has been in a monogomous relationship with another woman for seven years and counting. I have had one previous partner and my fiance has had none. Neither of us have ever contracted HPV. Do you think we should consider being vaccinated?
Dr. Murphy:
That is very much an individual decision. I am firmly convinced that the benefits outweigh the risks. Having said that, the risks in this woman’s situation are low. She does say that her partner had a previous partner. It’s implied although not stated that she herself has not had a previous partner…so certainly that’s got to be a low risk, but not no risk situation. In that situation, I’m quite sufficiently satisfied with the safety data that she’s very unlikely to come to harm, and then it becomes almost an economic issue. It’s expensive. Does she want to spend that kind of money when she’s at low risk?
One of the practical aspects of this is that it takes six months to administer the schedule – the three doses that need to be given – so again, if her circumstances ever change and she decides to take on another partner, she can’t have this kind of protection for six months. That should figure into the calculation. Whether she will decide to be vaccinated or not is very individual.
Tami Farrelly
I don't like the rush to market..
Was the vaccine tested on 12-13 year olds??
Personally I will not authorize the immunization, I am going to wait to see the results and I have to pay for the shot myself...so be it.
Aditi Garg
Should a person choose to abstain from sex until the time of marriage, and then proceed to maintain a purely monogamous relationship, is there still a need for them to get immunized? What is the degree of necessity then?
Dr. Murphy:
If in a mutually monogamous relationship, the chances of contracting general HPV is very low. Very, very low. Number one, there are not very many mutually monogamous couples with no prior sexual exposure history in this society we live in. Number two, even if that’s one’s intention upon marriage or commitment in a relationship…if that relationship were to fall apart…then presumably the vaccine would be wise to have. In theory, it works. In practice, it doesn’t happen very often that protection is available to an individual.
Host Bob Sudeyko:
If I’m not mistaken, I think the Catholic Bishops of Ontario’s position to the Catholic school boards…abstinence is the best prevention.
Dr. Murphy:
Absolutely. But it doesn’t work very well.
Host Bob Sudeyko:
What is the number of girls…in high school who have engaged in sexual activity?
Dr. Murphy:
At least 20 per cent. It goes up quite quickly, from about, as I said earlier, the age of 14, 13, and upwards. It’s at least 20 per cent. And what’s important here is that most of them aren’t using any protection, and most of them have multiple partners. It’s a common social behaviour in our society. Morals, judgements, ethics, totally aside, those are the facts.
Nick
Do the 1,350 new cases of cervical cancer and the 390 cervical cancer-related deaths last year in this country warrant such a comprehensive immunization program? Could the government's 300 million dollar investment in the Gardasil not be better used to find a cure for a more prevalent condition/disease? Also, do you believe that the significant side effects of the vaccination are worth the potential benefits of the vaccination?
Kim Baker
Why is the Ontario Government only funding free immunization for girls in Grade 8 and others will have to pay up to $400, if this immunization program is proven to be effective and recommended.
Dr. Murphy:
That’s a really difficult question and, of course, only the ministry can answer it with certainty.
Host Bob Sudeyko:
Because it could be given to somebody in Grade 10, 11, right?
Dr. Murphy:
It could but the greatest rewards to the individual as well as to the health system is to vaccinate girls before they have sexual contact. Thirteen is probably the oldest, farthest you’d like to push that because we know that there are very good statistics to say that in Canada, many 13, 14, 15-year-old girls are sexually active, and that curve starts to rise by 13. We wouldn’t want to make it any later. We think it’s really important that it be school-based because a) it’s expensive and the school-based publicly funded program is critical and b) records can be kept and c) there are three injections required under the current recommendations and the most likely way most girls will get all three is in a school-based program.
Why 13 (for Ontario) was chosen? Again, I can’t speak for the ministry. It’s to keep it in the schools. I think there are other vaccinations that happen…hepatitis being the major one. I think they were trying to spread it out so the girls and parents had less over a longer period. But I’m not sure of that…
Host Bob Sudeyko:
But there’s nothing in place say, for a 19-20-year-old woman, who has not been sexually active, but yet would like to be protected with the vaccine. Is that person going to have to pay for the vaccine?
Dr. Murphy:
Under the current situation in all provinces in Canada, the answer to that is yes.
There are advocates of what we call a catch-up system which in fact…and in fact, NACI (National Advisory Committee on Immunization) did favoured for instance, starting in Grade 6 and Grade 9 and then for three years, doing two classes per year…by that way you’d have a large contingent of the population…vaccinated. Clearly, it had something to do with funding. Again, I don’t know the details…I think it’s a matter of modeling the best effectiveness, the most cost-effective way of getting the best benefit way for the population.
Jason
Victroria
1)Is it true that the vaccine has not been tested on girls aged 9 - 13?
2)Do the rates of cervical cancer in Canadian women warrant $300 million spent on a vaccine for a cancer that is curable in most women with early detection?
Kat
Ottawa
What, if any effect does the vaccine have on a fetus if a newly vaccinated woman were to become pregnant?
Dr. Murphy:
Again, it appears probably not. It’s advised that women who are or maybe pregnant not be immunized because – even the slightest doubt – would make us want to avoid that. But again the way the molecule works – it theoretically would leave a fetus at little or any risk at all. But clearly we try to avoid it. I guess the question is would one want to terminate a pregnancy if the mother had been vaccinated at the early stages and that’s an individual decision. There’s no medical recommendation requiring it or even promoting termination. However, it’s sketchy data obviously because it’s been avoided - immunization during pregnancy.
Sushmita Roth
How long was the test trial phase for? How can we be certain that there are no long term negative effects years down the road for these children who are getting the injections?
Dr. Murphy:
As I said, we can’t with certainty say there are no longterm effects. This vaccine is unlike many others in that it contains only protein. It contains no viral DNA, no DNA of the organism for which it’s supposed to bring protection, and no synthetic chemicals. So the likelihood of it having longterm side effects is low as I said. We need to know with certainty. And that’s why we’re strong proponents of a registry of a surveillance system where we can not only assess the risk of this vaccine when given widely in the population but also the benefits. We want to know what we’re achieving with this vaccine.
Shannon
I was diagnosed with HPV while pregnant with my first child. Since then, I have had abnormal pap results, warts, and other stressful sexual health issues related to my HPV. If I had been vaccinated with this HPV vaccine when I was in grade eight, could all this have been avoided?
Dr. Murphy:
Almost certainly yes. And this is exactly the kind of thing that is sort of under the radar. I don’t think any public policy makers would have instituted this vaccine program just to prevent genital warts, or just to prevent abnormal pap smears. The thrust is about cancer but these are definite positive benefits that are less commonly focused upon and dealt with. There are other strains of the virus that can cause the problems that the caller relates to but most commonly they are caused by the strains that will be dealt with by the vaccine.
Gracey hitchcock
Would you allow/encourage your own (if you have/had one) daughter to have the vaccine?
Host Bob Sudeyko::
I suppose we know the answer to this. If you had a daughter that fell into this grade level for vaccination, I take it you have no hesitation.
Dr. Murphy:
I would have zero hesitation. I do not have a daughter, but I have many friends who do. I have many young women in my life who are important to me, and I would strongly encourage them all to have it.
Stephen Arif
Would it not be a better to vaccinate both boys and girls to reduce viral infection?
Why do we not vaccinate all teenage girls (and boys) now if this is a good thing?
Editor's note: Please see answer to Kathy's question.
Kathy
Since men can get and spread HPV why is the vaccine promoted as specific to women.
What were the demographics of the test group - how many people, what gender, what age?
Dr. Murphy:
So a vaccine can do a number of things. It can protect an individual or it can achieve what we call herd immunity which means to wipe the organism out of the population. So for instance, polio. By vaccinating everybody, we get herd immunity. The polio virus does not survive in the population. A decision has been taken at many fronts that with HPV, herd immunity is probably not the best way to go. Individual protection is.
And that’s why girls have been targeted because the main target disease is cervix cancer, which, of course, boys can’t get. We know males do have a very satisfactory immune response to this vaccine which had to be proven. That can’t be assumed that just because females respond well that males do, but in this case they appear to. So the question is what utility in terms of disease prevention…this is not about preventing HPV.
The strategy is not about preventing HPV in itself or wiping it out of the population. It’s about preventing cancer. Now there’s some pretty good evidence that there are some cancers of the anus, cancers of the penis and even some oral cancers that may be related to HPV and that information’s evolving and maybe in time we’ll change our approach. However, at the present time, even though men can become immune based on the virus, we’re not sure what protection it gives them in terms of cancer at least.
Host Bob Sudeyko:
What sort of test group...?
Dr. Murphy:
The original test group was a very broad sample from Europe, North America and South America, and it was women prior to beginning their sexual activity. Several studies have been done that had somewhat different designs but a very broad spectrum – all young, some younger than others. Then there were some studies done in more mature women, and the safety data is the same across all those groups. It’s a very safe vaccine in terms of the short term.
Again, the naysayers among us bring up the issue of long term, and absolutely we don’t have 20-year data on this vaccine. The way it’s made – it should be safe. That’s not good enough, of course. We need to be very mindful and vigilant about potential adverse effects over the long term. But it’s not our practice in our society to withhold beneficial innovations in health care because of the theoretical risk for something that should be safe.
Host Bob Sudeyko:
What about out of that test group, how many of those were girls in the 9-13 age group?
Dr. Murphy:
That’s a smaller portion of the groups that have been looked at but there have been several thousands in that age group.
karrie
toronto
is it true that even non-sexually active, or sexually active femailes using condoms can still contract strains of the HPV virus? My doctor has told me there have been cases of this. If these claims are true, isn't that more reason to vaccinate against the possible effects of abnormal cervical cell growth, especially because the origins of HPV are unknown?
kanchan
toronto
Is it true that studies have shown HPV can be contracted in abstinent women?
Also, is it true that the source of HPV is unknown and that condoms do not necessarily protect women from this virus 100%? My physician has told me these facts as a reason to get the vaccine. I would like to hear your thoughts on this.
Dr. Murphy:
Well, HPV…there are many different strains of it. Our conversation today is really mostly about the genital strains – the strains that are sexually transmitted, but there are strains that are probably not sexually transmitted. It appears to be a very old virus ..
Certainly we know the strains that are addressed by this vaccine and the one’s coming down the pipe are almost certainly, almost always, almost universally spread by genital contact.
This person who sent in the question is absolutely right. We know there’s a really good study recently published that shows consistent condom use partially protects – decreases the likelihood of spreading HPV.
Host Bob Sudeyko: But it’s not 100 per cent.
Dr. Murphy:
It’s nowhere near 100 per cent. And the key is consistency, especially if we’re talking about teenagers and young adults not in committed relationships. The likelihood of consistent condom use is pretty close to zero.
laura maclachlan
toronto
Is it true that the vaccine must be given every five years, or is this a one-time only shot?
Host Bob Sudeyko:
Tell us a little bit how the vaccination program is to work. I take it you need three shots and possibly a booster shot later on.
Dr. Murphy:
The possibility of a booster shot is one of many unanswered questions with this vaccine. It’s the immune response to both the vaccine that’s on the market now and one that’s going through the approval process and by the way has been approved in Europe…the immune response has been extremely good. So we know this vaccine causes our body to generate antibodies against the virus – these two strains of the virus – the cancer-causing virus.
It’s only been looked at in trials up to about six years; however, those antibody levels appear to be holding up quite level so that it maybe that longterm immunity is going to happen with the first three injections. Having said that, it’s an unknown. If we vaccinate young girls before they become sexually active, before the age at which they’re at greatest risk…if their protection wears out while they remain at risk, then boosters may be required. We know that there’s a very, very good immune response to being rechallenged in the vaccinated population so we know it’ll be effective if it’s required, but we don’t know if it’s going to be required.
Amy Cooney
Cervical cancer is hardly an epidemic in our country. Why, then, has Gardasil become part of the vaccination programme in our schools?
Host Bob Sudeyko:
This is as I understand it…is going to be the first mass vaccination in North America of its kind since the polio vaccine back in the 60s. During the time of the polio vaccinations, there was a polio epidemic underway. There is no HPV epidemic. What is the rush to move ahead with this now?
Dr. Murphy:
Well, I’m not sure that’s true. I think there is an HPV epidemic. There’s lots of information and fair bit of data to support the fact that HPV is very common. Now, we don’t have a lot of data as to how common it was a decade ago or a generation ago, but we know that women throughout their lifetime have approximately 70 to 80 per cent chance of having a HPV infection at some point and at any given time somewhere between 15 and 25 per cent of women in North America carry HPV so that’s pretty close to epidemic to me.