Measuring the success of the mandatory HPV vaccine
Posted on 24 October 2019
The mandatory vaccine HPV is designed to prevent cancer-causing infections and precancerous conditions of the cervix. Is it working?
Cervical cancer is a national health priority. Yet this is a preventable disease that could be eliminated with effective primary prevention measures.
“Cervical cancer is the leading cause of death in many developing countries,” explains Dr Laura Serfontein, a radiation oncologist at Mediclinic Cape Gate. “It’s the second-most common cancer in women in South Africa. In fact, some estimates show that one in 42 women here will develop the disease in their lifetime.”
The World Health Organization warns that the high prevalence of cervical cancer, and the associated high mortality rate, is largely related to a lack of access to education and treatment. If the disease is recognised early enough and managed effectively, it can be cured.
“There are over 200 sub-types of the human papillomavirus (HPV),” she explains, “and they are not all symptomatic or harmful. Strains 16 and 18 are the most oncogenic – and 99% of cases of cervical cancer are associated with these types.”
This is why the Department of Health introduced primary prevention measures to protect against the spread of cervical cancer in 2017. The mandatory vaccination of young girls against the human papillomavirus, together with the promotion of awareness regarding HPV prevention, is designed to prevent the development of cervical cancer and improve the health of women in SA.
This has been highly successful, says Dr Serfontein, who is based at Cancercare’s Cape Gate Oncology Unit and Treatment Centre.
Importantly, HPV is not exclusively a sexually-transmitted virus. “Most of the time, when you are exposed to HPV, your immune system can eliminate it. But sometimes, for various reasons, it survives inside the epithelial cells of the cervix, where it can lead to the development of abnormal, or dysplastic cells. This is usually an early warning sign of cervical cancer.”
The HPV vaccine aims to prevent that from occurring. “The vaccine was introduced to reduce the persistent HPV infection, and in time, to prevent the onset of cervical cancer.”
Schoolgirls between the ages of 9 and 12 in South Africa are now required to receive the HPV vaccine as a preventative measure. “Two vaccines have been introduced,” says Dr Serfontein: “Cervarix, which protects against the two high-risk strains of HPV, and Gardasil, which offers additional protection against low-risk sub-types.”
The roll-out of the vaccine came about as the product of large-scale collaborative efforts between the Departments of Health and Education, as well as a range of independent healthcare experts and advisors, beginning in 2014. The Cervical Cancer Prevention and Control Policy document was introduced in 2017, and the first round of the campaign took place during March 2018.
In order to be administered, parents of the schoolgirls needed to have given consent. “It was a lot more successful than initially anticipated,” says Dr Serfontein. “Over 350 000 Grade 4 learners have been vaccinated in over 16 000 public schools across the country. That shows 94% of SA schools were reached, and 86% of age-eligible girls were vaccinated. This shows that all stakeholders were highly successful in spreading the message: cervical cancer is a largely preventable disease, and this is a vital vaccine that could eventually lead to the complete eradication of cervical cancer.”