In this interview we discuss the latest on HPV vaccines for cancer prevention and some of the struggles countries face in achieving widespread adoption.
As part of our coverage of the 2015 European Cancer Congress, held September 25–29 in Vienna, we are speaking with Jack Cuzick, PhD, John Snow Professor of Epidemiology at Queen Mary University of London. At this year’s meeting, Dr. Cuzick will be participating in a session discussing the HPV vaccine for cancer prevention.
-Interviewed by Leah Lawrence
Cancer Network:The two HPV vaccines have been on the market for several years now. How has the use of these vaccines changed since they were first brought to market?
Dr. Cuzick: Well, very recently there has actually been a third vaccine that has been approved in the United States and most of Europe. It actually has nine types of HPV as opposed to the four types in Gardasil and the two types in Cervarix. Over the years there has been a move towards vaccines that have the two additional types-that is types 6 and 11-which protect against genital warts. That is why Gardasil has had more of the market more recently than Cervarix.
Cancer Network:Has there been any noticeable decrease in the rates of cervical or other cancers since these vaccines have been approved?
Dr. Cuzick: It is really too soon to see any impact on cancer rates. The vaccines are primarily given between the ages of 12 and 14 and cancer is very uncommon before the age of 25 or 30. We haven’t seen any impact on cancer rates as yet, and we don’t expect to do so for another 5 years or so. However, precursor lesions, so-called CIN lesions, we are already beginning to see an impact on those. They are detected in screening and are the precursors for cervix cancer. There is now clear evidence for a decrease in those in younger women.
Cancer Network:The vaccines have been proven to have high protection rates against multiple cancer types. Have rates of adoption of the vaccine been high, and, if not, what populations are still lacking?
Dr. Cuzick: The adoption rates are highly variable. Very high rates have been seen in the United Kingdom and in Australia where a school-based program has been instituted. Children can get vaccinated as part of the routine of attending school and [the vaccine is] covered by the government. High rates have also been seen in Denmark, which has a very effective clinician-based program.
In other parts of the world, even where there are adequate resources, there has not been the infrastructure to achieve high coverage rates. For example, [coverage is] 30% to 40% in the United States and that level or lower in much of Europe.
Cancer Network: Are there any specific populations? Is it more likely for younger females to get vaccinated than younger males?
Dr. Cuzick: The vaccination has been focused on girls between the age of 12 and 14, where these coverage rates have been very high. Only recently has the vaccine been offered to boys, initially in Australia. The reason for that initially was cost. The price of the vaccine has come down dramatically in terms of cost per dose. Australia and other countries are now adopting that to give in boys. For boys, the benefits early on will only be in genital warts, because the cancers they get typically occur much later in life. It will be many decades before we see an effect of the vaccine on cancer rates for boys.
Cancer Network:What is the future for these vaccines? What other cancer types or patient populations are being researched?
Dr. Cuzick: There is much interest in extending vaccine coverage to older women. One of the reasons that we haven’t done this initially is that the vaccine is not effective if you have already been infected with the virus. It is a prophylactic vaccine. It is not a therapeutic vaccine. However, with the new vaccines that may be covering as many as nine types [of HPV], it is unlikely that a woman will have been exposed to all of these types so there is a lot of interest in whether or not … older women need to be screened. They get one vaccination and that may provide almost a lifetime protection, which would be very nice for parts of the developing world such as Africa, South America, and parts of Asia.
Cancer Network:Great, well thank you so much for taking a few minutes to speak with us about this important topic.