TOPICS > Science

FDA Approves Use of Vaccine for Cervical Cancer

June 9, 2006 at 3:40 PM EDT

JEFFREY BROWN: Cervical cancer is the second-leading cause
of cancer death among women worldwide, killing more than 250,000 a year. And
while widespread use of pap smears has reduced its toll in the U.S.,
it still causes more than 3,700 deaths a year here.

Yesterday, the Food and Drug Administration approved the
first vaccine to prevent the disease. And here to tell us about it is Dr.
Elizabeth Garner, a gynecological oncologist at Brigham and Women’s Hospital in
Boston. For the
record, she has no affiliation with Merck, the company that is marketing the
new vaccine, called Gardasil.

Dr. Garner, I think it would help, first, to explain to us
how cervical cancer is caused so we can understand how the vaccine itself

DR. ELIZABETH GARNER, Gynecological Oncologist: Certainly. The
vast majority of cervical cancers are caused by a virus known as human
papilloma virus. This is a very common virus. By the age of 50, probably about
80 percent of women have been infected at one point in time during their lives.

Most women don’t get any problems from human papilloma
virus, but a minority of women, for reasons that aren’t entirely clear, develop
precancerous changes on the cervix, which, if left untreated, will develop
ultimately or can develop ultimately into cervical cancer.

JEFFREY BROWN: So the vaccine blocks the infection that, in
some cases, leads to cervical cancer?

DR. ELIZABETH GARNER: Exactly. Right. And the vaccine is
made of these small particles that are called virus-like particles that, to a
woman’s immune system, look exactly like the virus, so as if she has been
infected, but they don’t actually contain any of the actual viral material.

So, when giving the virus-like particles, one can elicit an
immune reaction that then can prevent the changes that develop in the cervix.

When to start protection?

JEFFREY BROWN: And how effective is this new vaccine?

DR. ELIZABETH GARNER: This vaccine is very effective. In arecent trial, it prevented pretty much 100 percent of the infections of HPV,the human papilloma virus, and also prevented about 100 percent of theprecancerous changes that can develop on the cervix.

It also is important to note that this vaccine also treatsor prevents the changes caused by a couple of other types of human papillomavirus which don't cause cancer, but which can cause genital warts and otherproblems. And the vaccine was also very effective at preventing those.

JEFFREY BROWN: Now, the vaccine was approved for girls andwomen aged nine to 26, but the big question at the moment is: At what ageshould it be given? Explain to us the issues here.

DR. ELIZABETH GARNER: So the main issue is that the vaccineis going to be most effective if it's given to a girl or a young woman beforeshe has become exposed to human papilloma virus.

JEFFREY BROWN: And -- excuse me -- that means before shewould be sexually active in...

DR. ELIZABETH GARNER: Exactly, because this is a sexuallytransmitted infection. And a recent study, actually, showed that by the age of13 about 7 percent of girls will report that they've been sexually active atsome point.

So, certainly by age 13, there's a significant number ofgirls who are already engaging in sexual activity and who already are likelyexposed to human papilloma virus, so one needs to try to target girls beforethey've been exposed.

JEFFREY BROWN: And this is because -- again, just to clarify-- it's not as effective once a woman has been infected?


Mandatory vs. morals

JEFFREY BROWN: OK. Now, another big question then is whetherthe vaccine should be made mandatory or remain voluntary, and I guess inparticular whether it should be required for schools, for children going toschools.

DR. ELIZABETH GARNER: Yes. And I think that's going to endup being a rather complicated question. Because it's a sexually transmittedinfection, it's going to be a somewhat different situation than for othervaccines, such as chicken pox and so on, that can be transmitted throughsomething as simple as a sneeze.

Human papilloma virus is not transmitted that way, and so itmight be a little bit more difficult to make the argument that it needs to bemandatory for school attendance.

JEFFREY BROWN: And here, in fact, there are some socialconservative groups who are raising questions about it.

DR. ELIZABETH GARNER: Well, certainly, because I thinksimilar to, for instance, oral contraception, one could be concerned that, ifone tells a young girl that she's now prevented from getting cancer, or atleast cervical cancer, that she will then interpret that as meaning she canhave sex at a younger age.

And so Merck is, I think, going to specifically market thisvaccine as a cancer prevention vaccine and not a vaccine for sexuallytransmitted infection.

JEFFREY BROWN: But how will the decision be made as towhether it is mandatory? Who makes that decision?

DR. ELIZABETH GARNER: The states will decide that. There's aNational Advisory Committee on Immunization Practices, which is a CDCorganization, and that organization will decide what the recommendations willbe, in terms of scheduling, and age, and those sorts of things.

But in terms of whether the vaccine will be mandatory forgirls to attend school will be a state decision.

Paying for protection

JEFFREY BROWN: All right. Next issue is cost. Myunderstanding is this requires three doses over six months for a total cost of$360, relatively expensive for a vaccine.


JEFFREY BROWN: So is it expected that it would be coveredunder most private insurance plans?

DR. ELIZABETH GARNER: Well, certainly, if it's a mandatoryvaccine, I think it will be covered. You know, whether it's going to be coveredif it is voluntary, I think, is definitely yet to be determined.

There certainly are a lot of arguments for making it, youknow, a covered vaccine. This is something that is being given, you know, toprevent a potentially lethal problem. So I do think there are arguments towardsmaking it something that's covered, but, you know, it's definitely yet to beseen.

JEFFREY BROWN: But that would also weigh on various stateprograms that would have to provide it, I guess? And, of course, also for theuninsured...


JEFFREY BROWN: ... it's a big cost.


JEFFREY BROWN: Now, cost also is a factor -- we've beentalking mostly about the U.S.,but, as I said, this a larger problem worldwide. In the developing world, costswould no doubt be an even bigger factor. Tell us about the situation there andwhat kind of programs either are planned or might be planned to help.

DR. ELIZABETH GARNER: Sure. I think that Merck has indicatedthat they have several ideas in place.

One is that I believe they've been in contact with the Billand Melinda Gates Foundation, who have certainly expressed some interest inhelping in vaccine distribution.

I think that also the company has indicated that they willbe willing to, you know, think about and consider differential pricing andperhaps selling the vaccine at cost. And I think these are potential ways tomake it more available.

JEFFREY BROWN: And I mentioned earlier that the incidence isdown in the U.S. because of pap smears. Is the situation in the developingworld as bad as it is because pap smears are not used as much?

DR. ELIZABETH GARNER: Yes. In fact, in this country, whenthe pap smear was introduced as widespread screening, we saw the incidence ofcervical cancer drop about 70 percent, but those pap smear programs are notavailable in many parts of the developing world. And so we still see high ratesof cervical cancer.

Staying vigilant

JEFFREY BROWN: And I noticed that officials are stilltelling women that they still should get pap smears, even with this vaccine. Whyis that?

DR. ELIZABETH GARNER: Well, part of the reason is I thinkthat it's not quite clear, in fact, how long, what the longevity is of theprotective response from the vaccine.

Initial studies suggest that there certainly is protectionup to about five years. But, you know, if you are giving the vaccine to girlsat the age of nine or 10, that only takes them to their teenage years, so Ithink there's still some questions about the durability of the protectiveeffect.

Also, the vaccine covers HPV types 16 and 18, but there arecertainly other hybrid types of HPV that also are known to cause cervicalcancer. Types 16 and 18 cover or protect against -- or I should say cause about70 percent of cervical cancer. So you've still got about 30 percent of cancersthat are caused by other strains of HPV.

JEFFREY BROWN: And when might this new vaccine be on themarket?

DR. ELIZABETH GARNER: Well, certainly Merck has indicatedthat they will do everything to have it out and available within about a monthof FDA approval, so I think it will be available quite soon.

JEFFREY BROWN: All right. A lot of questions, but I guess avery exciting development.


JEFFREY BROWN: So, Dr. Elizabeth Garner, thank you verymuch.