The first product, launched by GlaxoSmithKline (GSK) in February, protects against HPV types 16 and 18 – which cause cervical cancer.
MSD's product, a quadrivalent recombinant vaccine, also guards against types 16 and 18, but extends protection to include strains 6 and 11 which are responsible for genital warts.
This product is priced at R770 per injection, compared to R700 charged for the GSK product.
Cervical cancer a real threat
Cervical cancer is the main cancer affecting South African women. "One in every 31 women is diagnosed with cervical cancer in her lifetime and it kills over 3 400 women in South Africa each year," says Martha Molete from the Cancer Association of South Africa (CANSA).
According to Molete, the vaccine could save hundreds of thousands of lives and could eradicate cervical cancer in time.
In over 80 percent of cases, cervical cancer is caused by the human papilloma virus (HPV), which is a very common sexually transmitted infection. It is estimated that between 60 and 80 percent of all sexually active individuals may be infected.
Although the strains of HPV that causes cervical cancer (HPV 16 and 18) don't affect men, they are carriers of the disease and can infect their female sexual partners.
The vaccine is already in use in the UK and the US, and is recommended for use in girls and women from the age of 10 upwards.
Cervical cancer - a background
Cervical cancer is a common disease in the developing world. Pap smears are currently the recommended method of screening, according to the World Health Organization (WHO) and the International Agency for Research on Cancer (IARC).
Although it is a preventable disease that is curable if detected and treated in its early stages, it remains the leading cause of cancer-related deaths in South African women, according to the Medical Research Council.
Factors that increase a woman's risk for developing cervical cancer include early sexual activity, multiple sexual partners and smoking.