To vaccinate or not to vaccinate

From the mistaken fear that it causes mental retardation to the debate over whether it encourages sexual promiscuity, the vaccine against the human papillomavirus (HPV) has recently received quite a bad rap. The backlash from the medical community against presidential hopeful Michelle Bachmann likely set the record straight on the mental retardation issue (it’s never been linked to even a single case). But whether, when and whom to vaccinate is still controversial. So, ignoring all of the hoopla that often tends to conflate scientific facts with political fiction, here are some answers about what the disease is and how the vaccine works.

What is HPV and whom does it affect?

HPV is a sexually transmitted virus. Though it is often undetected, it can lead to genital warts and lesions, which are the precursors to cervical, anal, penile, vulvar, vaginal, and potentially mouth and throat cancer. HPV is the only known cause of cervical cancer. Annually, cervical cancer kills approximately 300,000 women, making it one of the highest causes of cancer death in women globally.

Globally, HPV is the most common sexually transmitted infection. It will infect half of all sexually active men and women in their lifetimes. Most of them will never know it.

Due to the wide-spread nature of the disease, it is suggested that everyone is vaccinated — men and women.

Why was the vaccine developed?

Screening for cervical cancer via conducting pap smear tests are imperfect, Many women are never even screened.

The two vaccines, Gardasil and Cervarix, prevent up to70 percent of cervical cancer cases and 90 percent of genital warts cases when proper protocol is followed.

How do the vaccines work?

The HPV vaccines are administered in three shots over a period of six months. The second shot is given one to two months after the first, and the third shot six months after the first.

The vaccine uses the same strategy as most standard vaccines — it creates a harmless version of the original virus in order to train the immune system to fight the real virus. The shot contains recombinant viral-like particles (VLPs) that are created from HPV genes and mimic the shape of the virus’ VLPs. The vaccine’s VLPs are not dangerous because they contain none of the DNA or RNA of the original virus. When the vaccine enters the bloodstream, the VLPs are attacked by the body’s immune system. After killing them, the immune system holds the memory of the shape of these particles. Then, if the actual HPV later enters the bloodstream, the body is prepared to immediately kill it.

The vaccine requires three shots because the immune system must be exposed to tame VLPs three times to acquire substantial immunity. It is much more effective if patients are vaccinated before becoming sexually active, because if there is exposure to HPV prior to getting the vaccine or during the six-month process, infection is still possible.

Several clinical trials have shown that the vaccine has no serious side effects.

Why the controversy?

Unlike most vaccines that protect against childhood diseases, cervical cancer and other HPV-related illnesses do not affect people until much later in life, after sexual activity. This causes people to perceive the vaccine as less important, and overall it has been adopted more slowly than anticipated.

Also, it is the first vaccine for a sexually transmitted infection. Thus, it requires acknowledging that many teenagers have sex – something many parents don’t want to talk about.

Though it began as a vaccine only for females, the federal Centers for Disease Control and Prevention recently approved it for males as well. Full endorsement by the CDC will make insurance companies more likely to cover the vaccination, and as a result, will ultimately shift much of the cost — more than $300 per three-shot vaccination —  over to the government. Some are hopeful that the endorsement will cause it to slowly join the list of vaccines that are administered with little debate, but based on its journey so far there’s little reason to believe the clamor over the HPV vaccine will die down anytime soon.