Vaccination against cervical cancer: Can we prevent cancer?

Even though, cervical cancer is widely known as a preventable cancer, around 900 to 1000 new cases of cervical cancer reported in Sri Lanka every year. This is the second commonest cancer among females in Sri Lanka. Two main prevention strategies have been introduced to prevent this. Traditional cervical cancer screening program with Pap smears can detect this cancer in early stages so that complete cure is possible. The new approach is to prevent cervical cancer by vaccination. The cause for this cancer is infection of the womb neck with Human Papiloma Virus (HPV).  Therefore, if you are  vaccinated against HPV infection it is very unlikely that you will get a cervical cancer in the future.

HPV infection is a common infection and it does not usually cause symptoms. Therefore, you do not know whether you are infected with HPV or not. This virus spreads via sexual contact. So even if your daughter waits until marriage for sexual debut, or only has one partner in the future, she could still be exposed if her partner has been infected. Therefore, vaccination is the only effective preventive strategy for HPV infection hence the cervical cancer. This vaccine can prevent most cases of cervical cancer by protecting women against HPV infection. There are many types of HPV virus. However only few types of the virus causes cervical cancer. Two main high risk HPV types are type 16 and type 18.

Currently, two types of vaccines providing protection against high-risk HPV types 16 and 18 have been licensed, and both of them are now available in Sri Lanka.

1. The    bivalent    vaccine    (effective against    types    16    and    18    only)

2. The    quadrivalent    vaccine    (contains    additional    protection    against    types    6    and    11,    which    are responsible for 90% of warts in anogenital area).

Vaccine does not cause HPV infection because it does not contain active HPV virus. Both vaccines contain virus-like particles (VLPs), which are pieces shaped like the outer surface of a HPV. The vaccines stimulate development of antibodies against these VLPs, which, will prevent HPV infection in case of later exposure. The vaccines can prevent the infection if a girl is vaccinated before her sexual debut.

Safety and efficacy of these vaccines are evaluated in clinical trials and considered very safe and effective.