HPV Vaccination

Dr Dave HawkesSunday 22 December 2013 7:30am

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• (1Just a few weeks ago, Katie Couric – one of America’s most popular journalists and talk show hosts – caused controversy when she presented a segment on her show where the effectiveness of the HPV vaccine was debated. In her own words, Couric said: “We’re hoping to tell both sides so parents can make informed decision.” 

Here at Mamamia, we’ve always maintained a strong position that no – the effectiveness of any vaccine should not be debated. Because when it comes to vaccination, there is no other side. Just science.

And that’s why we asked Dr Dave Hawkes to put together a cheat sheet for us on the HPV vaccine.

So should we be worried about HPV vaccination?

Vaccination has always been a hot button topic, but since its introduction in 2007 human papillomavirus (HPV) vaccine has attracted more than its fair share of controversy.

The most recent examples of this are the episodes of American daytime TV shows “Katie” and “The Doctors” which examined the “controversy” of HPV vaccination.

The host of “Katie”, well-known journalist Katie Couric, interviewed parents who claimed that the HPV vaccines could cause serious injury and death. Dr Rachel Ross from The Doctors has given several reasons, including side effectsand the Japanese governments withdrawn recommendation, as to she does do not give the HPV vaccine in her practice.

So should we be worried about HPVvaccination?

Here are answers provided by science to five of the most common questions based on a research paper I recently published on the risks and benefits of HPV vaccination.

Does the HPV vaccine stop cervical cancer?

This is one of the most common questions and it is a little bit harder to answer because it takes between 10 and 20 years for cervical cancer to develop following HPV infection and the vaccine has only been available in Australia since 2007.

About 70% of cervical cancers are caused by only two of the 15 strains of HPV associated with cancer. Both HPV vaccines available in Australia (Gardasil and Cervarix) target these two strains (HPV Types 16 and 18). Gardasil also targets two strains linked to genital warts.

HPV infections lead to pre-cancerous lesions, which act as early warning signs for cervical cancer. Two of the more serious pre-cancerous lesions are called CIN2 and CIN3 and are likely to lead to cervical cancer 5% and 12% of the time, respectively. HPV vaccination has been shown to reduce CIN2 and CIN3 lesions by over 99% and this suggests that we are likely to see a drop in cervical cancer rates over the next decade.

In addition to cervical cancer HPV has been linked to a number of other cancers such as those of the penis (40% are HPV-associated), vulva or vagina (40%), anus (90%), mouth (3%) and oropharynx (12%).

If you get regular Pap smears do you still need to get the HPV vaccination?

Pap smears are a very effective way of detecting abnormal pre-cancerous cells (lesions) on the cervix, which allows them to be removed before they turn into cervical cancer. However the removal of these lesions can lead to complications during pregnancy such as giving birth to pre-term or low birth weight babies.

HPV vaccination prevents the infection before it can lead to a pre-cancerous lesion requiring treatment. It is still recommended that women who have been vaccinated still have regular pap smears because the current vaccines don’t protect against all cancer causing HPV strains.

Talk show host Katie Couric examined the “controversy” of HPV vaccines.

Why has Japan stopped recommending HPV vaccination?

In June this year the Japanese government withdrew its recommendation for the HPV vaccination. The government had received 1968 reports of side effects associated with the HPV vaccine and took the precaution,arguably for political rather than scientific reasons of removing its recommendation. 43 of these cases were examined and no link to the HPV vaccine was found. There have been more than 3.28 million people given the HPV vaccine in Japan since 2010 and 9000 women develop cervical cancer each year.

Does the vaccine only last 5 years?

HPV vaccines have only been available in Australia since 2007 so it is difficult to know exactly how long the protection will last. However recent evidence based on the women vaccinated during the HPV vaccine clinical trials suggests that it is at least 8 years with no cases of HPV found in any of the vaccinated women.

Does HPV vaccination cause serious side effects such as infertility or even death?

Like any medical procedure, HPV vaccines can have side effects. However most reported side effects (>93%) are minor, such as fainting, headache and injection site soreness, and disappear in a few days.

In terms of serious side effects, 7 clinical trials of over 44,000 women showed no differences between the HPV vaccinated and unvaccinated groups.

Once a vaccine is released for the general public a different type of safety monitoring begins calledpost-marketing surveillance. This monitoring allows anyone to make a report online of side effects they think might be caused by a vaccine. These reports are often the basis for claims, such as those presented on Katie and The Doctors, that the HPV vaccine causes infertility, autoimmune diseases or even deaths.  However when these claims have been investigated no link between premature death or autoimmune has been found.

There has not been a detailed investigation of the infertility claims of the two sisters presented on The Doctors, but previous internet claims of vaccine induced infertility have been found to be without substance.

Conclusion

The current evidence of over 1000 published scientific studies indicates that benefits of HPV vaccination far outweigh the risks.  However it is likely that we will continue to hear about these reported side effects because controversy sells, especially on TV.

Dr Dave Hawkes is Molecular virologist exploring the world of neuroscience at The Florey and then trying to explain it to his mates at the pub.