HPV Vaccine and Cervical Cancer

By Shazan Chughtai

In the UK, one thousand women die each year from cervical cancer. The good news is that this statistic may see a decrease with the introduction of the HPV vaccine. Despite how the tragic death of Jade Goody last year raised awareness about cervical cancer, there is a large amount of misinformation regarding cervical cancer and the human papilloma virus (HPV) vaccines. Because the HPV vaccines have been shown to significantly reduce the incidence of cervical pre-cancer, they may have the potential to save millions of lives around the world.

What is HPV, and why is it important?

There are thought to be over 200 strains of the human papilloma virus, of which 30 to 40 strains are thought to infect the human genitalia. The HPV is the most common of all of the sexually transmitted infections. It is transmitted by oral, anal and genital sex. In most cases, the body is able to clear the infection within approximately 1-2 years. In some people, however, the virus is not cleared by their immune system. In these cases, particular strains of HPV may go on to cause warts and genital cancer.

Research has also shown that particular HPV strains are directly responsible for various cancers. In particular 2 strains, 16 and 18, are responsible for 70% of cervical cancers. We now have two vaccines available which have been shown to provide immunity to these cancer-causing strains and preventing pre-cancerous damage.

Can I get tested for HPV?

There are tests available to indicate whether an individual has been infected with HPV and to identify which particular strains have been introduced into the body. Unfortunately, these tests are not available on the NHS; typically, they are only available in the private sector.

How does the vaccine work?

There are currently two vaccines used to treat HPV: Gardasil®and Cervarix®. Both provide immunity to cervical cancer causing strains 16 and 18. In addition to those two strains, Gardasil®also provides protection against strains 6 and 11, which are known to be responsible for genital warts.

The vaccines work by introducing small bits (antigens) of the particular cancer causing strains in to the immune system. It is important to realise that these small "bits" cannot cause the HPV infection. In most people, the immune system will react to these "bits" and create a memory of these particular HPV strains. In the future, should the body be infected by one of these strains, the immune system will recognise them immediately. The body's immune system will then mount a swift response, clearing the virus, and hopefully preventing it from remaining in the body where it can fester and damage cells, causing cervical pre cancer.

To build adequate immunity, the vaccination program involves having three jabs. After the first injection, the second injection is taken one month later. The third injection is administered four months after the initial injection for Gardasil®and 6 months after the initial injection for Cervarix®.

Is the vaccine safe?

Neither of the vaccines contains the actual virus. Studies on both vaccines have shown that the most common side effect was pain and swelling at the site of injection, much like with most childhood vaccines. Between 1-10% of Gardasil®vaccine recipients suffered bruising and itching at the site of injections and developed a raised temperature. Between 1-10% of Cervarix®recipients suffered diarrhea, muscle and joint pains.

Both vaccines are not recommended for women who are pregnant. With regards to breastfeeding, GaradsilĂ’ was shown to be safe, though we have no similar data for Cervarix®.

The UK national vaccination program began in September 2008 using the Cervarix®vaccine. Since that time, there has been nothing to indicate that the vaccination is harmful in any way, which would require the program to be terminated.

Who can have the vaccine?

Trial data shows that the vaccination is not effective in women who have already been exposed the strains 16 and 18. As HPV is sexually transmitted, it is ideal to vaccinate people before they become sexually active.

As both sexes transmit the virus, both can be vaccinated. However, it is believed to be more cost effective to vaccinate females only. The thought process behind this is that if enough females are vaccinated, then there should be no real need to vaccinate males.

Currently, the NHS vaccination program is aimed at young girls aged between 12-13, though a catch up program will offer 17 year olds the vaccination. The vaccination is also available privately from Care Quality Commission (link) registered clinics.

How long will the vaccine protect me?

Current published research shows that protection against HPV infection and cervical pre cancerous change lasts at least five years. It will be several years more before we find out if it lasts even longer. It has yet to be determined whether a booster vaccination will be required and how well the vaccine works at reducing the number of new cases of cervical cancer.

Where can I get the vaccine?

The vaccination program is being offered at the following places:

* Secondary Schools
* GP surgeries
* Private Clinics

The vaccine is not available by prescription. The Department of Health has classified it as a childhood vaccine, which can only be available through Primary Care Trusts (PCTs). It is the duty of the PCTs to distribute the vaccine to NHS surgeries and schools, where it will be administered.

Do I still need to go for smears?

Yes! It is crucial for every woman to go for regular cervical smears. No vaccine offers 100% protection. Furthermore, although it is hoped the vaccine will prevent the most common form of cervical cancer known as squamous cell carcinoma, it is not yet known whether the vaccine protects against adenocarcinoma (another form of cervical cancer). Pap smears, physical examination and preventative measures (link) remain an absolute essential when it comes to screening and prevention of cervical cancer.

Conclusion

I strongly urge women to get vaccinated against HPV. Why take the risk of not getting the vaccine when it could save your life? If you are not already sexually active, then you are in the ideal position of receiving the benefit of the vaccine. If you are sexually active, you can minimize your risk of contracting HPV by staying in a monogamous relationship. Use condoms if you have multiple partners (though there is still a chance of getting infected through any skin contact which is not protected by a barrier). Finally, never miss a pap smear. Early detection of pre-cancerous cells is crucial to preventing cervical cancer.[source]

0 comments:

Post a Comment