An experimental vaccine from Merck & Co. seemed to deliver a wider scope of protection against a cancer-causing virus as compared to the company's Gardasil shot based on clinical trials.

According to the Wall Street Journal, the pharmaceutical company expressed that the results of the study made them decide to submit the new vaccine, dubbed as V503, for the regulatory approval of the U.S towards the year's end. This could then lead to the product's market launch as soon as the coming new year. Merck is expecting that health-care providers will eventually change to V503 once the product gets marketing approval. Some analysts have even predicted its annual sales to exceed the $1 billion mark.

Launched in 2006, Gardasil was the initial vaccine to protect against Human papillomavirus or HPV which is a sexually transmitted virus that causes cervical cancer among women and other sub-common types of cancer in both men and women. The U.S Centers for Disease Control and Prevention recommends boys and girls age 11 and 12 to receive HPV vaccination. However, those ages 9 to 26 are also allowed to get the same vaccination. GlaxoSmithKline also has an HPV vaccine called Cervarix.

Gardasil was designed to protect against a quadruplet strains of HPV. Two of them are believed to be responsible for around 70 percent of all cases of cervical cancer. The other two are the main culprits in causing genital warts. On the other hand, Gardasil doesn't protect against several other strains of HPV wherein some are said to also cause cervical and other forms of cancer.

To close the gap and perhaps widen the coverage, Merck has designed the V503 vaccine that promises to protect against nine strains of HPV. The company simply added five cancer-causing HPV variants to the four that are already included in Gardasil. The wider scope is believed to cover almost 90 percent of all cervical cancer cases around the globe, said Alain Luxembourg, clinical research for adult vaccines director in the R&D unit of Merck.