Cervical Cancer Vaccines- What you should know!

Cancer is a much- dreaded disease, since very few afflicted by it can escape its claws. Just like the deadly crab that the name literally stands for, it has the capacity to sting each and every organ and lead to a life that is brief but filled with misery and pain. Unfortunately, the knowledge of most people about the disease is limited to ghastly images of patients with oral cancer, and the fact that chewing tobacco or smoking can lead to cancer, thanks to what has been portrayed to us over the years. There are many types of cancers much beyond the realm of those shown in the educational advertisements in the movie theatres, or the images one sees on the cigarette packs.

Every woman, and for that matter every man too should be aware of a very common but preventable type of cancer, viz. cervical cancer. The same agent responsible for this cancer can also cause other cancers such as cancers of the penis in men, or a few types of cancers of the throat or anus in both men and women.

What is cervical cancer? What is its cause? What are the risk factors for a woman to develop cervical cancer?

The mouth of the uterus in a woman is called the cervix. It is the organ that can be felt at the inner end of your vagina. Cancers of this part of the body are called cervical cancers. Cervical cancers are the 4^th most common cancers in women.

Human Papilloma Virus (HPV) is the agent responsible for most cases of cervical cancer. This virus causes certain changes in the genetic material of the cells- it turns off certain helpful genes called tumour suppressor genes, and causes abnormal proliferation of the cells. There are more than 150 types of HPV. Not all of them may be harmful.

As per the statistics stated by CDC (Centre for Disease Control), 80% of people will get an HPV infection in their lifetime. Most of the people infected with HPV may not get any symptoms, and most of the infections resolve on their own. A few types of the virus, namely HPV 6 and 11 can cause genital warts, whereas the most dangerous forms of the virus are HPV 16 and 18, which are mostly responsible for 70% of cervical cancers. Apart from cervical cancers, they may also cause cancers of the penis in males, or cancers of the throat and anus in both males and females. Once infected with HPV, it may take 10- 20 years to progress to cervical cancer.

HPV may be transmitted sexually, or by skin to skin contact. Women with certain risk factors stand a higher chance of developing cervical cancer. Smoking, earlier age at marriage (or first sexual exposure), weakened immunity as is commonly seen in diabetics, HIV positive women, coexisting infections such as Chlamydia, a diet low in fresh fruits and vegetables, lower socioeconomic status, women with multiple sexual partners, have been implicated as the risk factors for developing cancers of the cervix.

What are the types of cervical cancer vaccines? Who should receive the vaccine and when?

CDC has stated that HPV vaccination can prevent more than 29,000 cases of cervical cancer yearly.

There are 2 main types of cervical cancer vaccines available in India- Cervarix (Glaxo- SmithKline) and Gardasil (Merck). Cervarix (also known as the bivalent vaccine) protects against HPV 16 and 18, the two main cancer- causing types of the virus. Gardasil (also known as the quadrivalent vaccine) provides protection against 4 types of HPV, namely HPV 6, 11, 16 and 18. Thus, it also protects against genital warts in addition to the cancers. In the United States, a nonavalent vaccine called as Gardasil-9 has also recently been launched, which covers 9 types of HPV.

Since the aim of the vaccine is to develop immunity in the body before exposure to the virus, theoretically, one must receive the vaccine before the first sexual exposure. Hence, the primary target group for receiving the HPV vaccine in most countries is young adolescent girls aged 9- 14 years.

CDC recommends that the vaccine be given to females aged 13 through 26 years and males aged 13 through 21 years not adequately vaccinated previously.

Vaccination is also recommended through age 26 years for gay, bisexual, and other men who have sex with men, transgender people, and for immunocompromised persons (including those with HIV infection) not adequately vaccinated previously.

However, FOGSI (Federation of Obstetrical and Gynaecological Societies of India) guidelines state that the vaccine can be given to all women between the ages of 10 and 45 years, under the premise that even though they have already been exposed to one type of the virus, they may achieve protection against the other types and can still help prevent genital warts and cancers.

How many doses of the vaccine need to be taken?

WHO recommends that 2 doses of the vaccine be given to girls less than 15 years of age, 6 months apart. However, if the age is above 15 years, 3 doses may need to be taken.

Does the vaccine have any side effects?

The vaccine being an inactivated one, side effects are very few, if any. Some women might experience pain and swelling at the injection site. This may be lessened by applying an ice pack. A few might have fever, body ache or flu- like symptoms for a day or two. Severe reactions are rare, and the vaccine is generally well- tolerated.

Can I take the vaccine during pregnancy? Do I need to delay planning a pregnancy after finishing my HPV vaccination course?

Large studies are lacking regarding the safety of HPV vaccine during pregnancy. However, if a woman inadvertently discovers that she is pregnant after taking an HPV shot, that in itself is not a reason to terminate the pregnancy. There have been several instances where women who have taken the HPV vaccine and then discovered that they are pregnant have had an uneventful pregnancy course and delivered healthy babies. However, if you have taken one dose of the vaccine and then discover that you are pregnant, it is advisable to take the rest of the doses after delivery.

There is no need to delay pregnancy after completion of the vaccination course, it is quite safe to conceive immediately afterwards.

The author is a dynamic and highly approachable Obstetrician, Gynaecologist and Infertility Specialist practising at Phadke Hospital and Dr. Patankar Clinic in Pune.