A beautiful blue and green mass with stars covering its surface, the human papillomavirus (HPV) is ironically beautiful. Not only is HPV pretty, it is also very small. All viruses, like HPV, are small, consisting only of genetic material and protective coatings made of fats and proteins. Due to this simplicity, the only way viruses can replicate and spread is by infecting other organisms’ cells. Viruses are so reliant on their hosts that some have evolved to be entirely specialized on one species. In particular, HPV is dependent on humans to replicate.
HPV’s dependence on humans is what makes this beautiful virus deadly. According to Kansas State University’s Dr. Nicholas Wallace, this virus turns infected humans into “HPV factories,” so more and more cells in the human body carry the virus over time. As HPV spreads, it hijacks cells, causing them to grow too fast. With these changes, there is a potential risk for this beautiful-looking virus to promote uncontrolled cell growth, better known as cancer.
HPV is typically described as a highly prevalent, sexually transmitted disease. However, Dr. Wallace explained that the definition of “sexual” transmission is very broad. HPV can be contracted through minimal contact, and condoms do not always prevent infection. HPV is so easy to get that 85-95% of people with only 1 sexual partner carry some form of HPV. You can imagine the percentage of people with HPV gets really close to 100% with increasing numbers of sexual partners.
If HPV is so prevalent, why aren’t we all walking blobs of cancer? Dr. Wallace answered this question by explaining the importance of infection times. From the time someone first becomes infected with HPV, it typically takes 10-30 years for cancer to develop. While HPV is good at hiding from our immune systems, most people’s immune systems can find the virus during this long period of time before cancer develops. Although most people can fight off HPV infections, many people cannot. Because this virus is so common and easy to spread, there are still many people that will develop cancer following HPV infections.
Dr. Wallace studies HPV to help provide better treatment to those that do develop cancer. Understanding how HPV causes cancer may help doctors provide treatments that are more efficient and less damaging to patients than current options.
Although Dr. Wallace loves his research, he said that his lab should be “put out of business”. Vaccines are available to prevent people from getting HPV in the first place. Although HPV vaccines are relatively new (they were first released in 2006), data so far indicates very promising results; the vaccines are very effective at preventing HPV and have minimal side effects (as long as you are not afraid of needles!).
This leads us to an important question: If we have effective HPV vaccines available, why do people still get HPV cancers?
The first piece of this puzzle relates to who is actually getting HPV related cancers. Males have a higher risk of developing HPV related cancers than females, and this is possibly due to several factors. First, when HPV vaccines were first released, they were largely targeted towards young females because HPV is typically associated with cervical cancer. Because many males do not have cervixes, consequences of HPV were historically considered to be worse for females. This is a common misconception, however, as cancers caused by HPV can develop on any mucous membrane. This means HPV can infect any genitalia, not just cervixes, as well as the throat, making everyone vulnerable to HPV cancers. Because young females were the primary population receiving HPV vaccines when it first was released, many young males were never vaccinated.
Another important factor to consider when thinking about HPV cancers is screening. In addition to more females historically receiving vaccines than males, females are also screened more often for cancers as part of wellness exams. Due to these frequent screenings (Pap smears and physical examinations), even if females are not vaccinated and do carry HPV, signs of cancer are typically caught very early. Males do not have regular screening for HPV cancers. If a male starts to show symptoms of a throat or genital cancer due to HPV, it has typically progressed far enough that treatments will be highly intrusive.
Cancer is associated with all kinds of different risk factors. HPV related cancers are one of the few that we can actually take easy steps to prevent. Let’s all work to put Dr. Wallace’s lab out of business and spread the word about getting HPV vaccines. As beautiful as the HPV virus is, we can imagine something even more beautiful – a world without HPV.
The post was written by Lindsey Bruckerhoff. She is a PhD student at Kansas State University interested in how landscape change and predators influence stream fish communities at multiple spatial scales.