Cancers derive from cells within our own body that have gone haywire. But did you know that some viral infections are responsible for these cell changes and can cause cancer? These events are unusual, but can lead to many different types of cancer, including cervical cancer, Burkitt’s lymphoma and Kaposi’s sarcoma. The human papillomavirus (or HPV for short) is the best-studied and well-known example of virus associated with cancer. Canadian Cancer Society funded researchers, along with scientists worldwide, helped pinpoint HPV as the cause of almost all cervical cancers. This was an extremely important finding because cervical cancer is the second most common cancer in women, worldwide. Thanks to this discovery, vaccines against HPV were created that can save lives. Unfortunately HPV vaccines have recently been facing unjustified controversy in the media. I would like to take some time to respond to these unfounded doubts and explain what HPV is and why HPV vaccination is good for our health.
HPV virus is the most common sexually transmitted infection. Around 75% of Canadians will catch the virus at least once during their life. While only a few of these infections will be life threatening, some will lead to the development of cancer. In Canada, this corresponds to 1,450 newly diagnosed cervical cancers and around 400 deaths amongst women every year. HPV can also cause cancer of the vagina, penis, anus and, throat (1, 3).
Since the HPV virus causes these cancers, they can be prevented by vaccination. Scientists, pharmaceutical industries and the medical field have been working on this idea for a long time. Today we have access to two commercialized vaccines that are scientifically proven to be safe and very efficient. In Canada, we mostly use the vaccine Gardasil, which has been approved in more than 130 countries and has already safely been used amongst millions of girls worldwide (2, 3). This vaccine also has the potential to prevent vaginal, penile, anal and throat cancers.
Unfortunately, you might have heard through the media that some girls became very sick after vaccination (2). Although tragic stories, there was no conclusive evidence directly linking the vaccine to the illnesses. If we consider millions of people, there is a certain chance that these tragic events will happen independently of the vaccination. Similarly, out of all the girls that have been vaccinated against HPV, some might have won an important scholarship. It doesn’t mean that the scholarship was caused by the vaccine (2). If one thing happens just after another, it doesn’t mean that the first one caused the second. This misleading conclusion often causes unjustified critiques and prejudice to our healthcare system.
Before arriving on the market in 2006, Gardasil was part of 2 huge clinical trials involving more than 10,000 women from around the world (1). Results clearly demonstrated that the vaccine was safe and effective. Since 2006, 170 million doses of Gardasil have been distributed worldwide and the only serious (and very rare) side effect that has been associated to the vaccine was allergy. The benefits of such a vaccine are so important that they outweigh the mild negative side effects.
HPV vaccine is a fantastic medical success and an important advancement in how we can prevent cancer. I believe this vaccine will provide women all over the world with better health outcomes and give us an important advantage against cancer.
This article was written by Catherine Brun. She completed her PhD in Zurich, Switzerland and currently works as a post-doctoral researcher in the lab of Dr. Dan Durocher at Mount Sinai Hospital in Toronto studying DNA damage.
(1) FX Bosch, TR Broker, D Forman at al., Comprehensive control of human papillomavirus infections and related diseases, Vaccine, December 2013
(2) Toronto Star: http://www.thestar.com/opinion/commentary/2015/02/11/science-shows-hpv-vaccine-has-no-dark-side.html
(3) The Society of Obstetricians and Gynaecologists of Canada (SOGC):