Complex sentence: Some types of cancer, such as cervical cancer and some liver cancers, are caused by viruses (oncoviruses), and traditional vaccines against those viruses, such as HPV vaccine and hepatitis B vaccine, will prevent those types of cancer.
Split into simpler sentences: Some types of cancer, such as cervical cancer and some liver cancers, are caused by viruses (oncoviruses). Traditional vaccines against those viruses, such as HPV vaccine and hepatitis B vaccine, prevent those types of cancer.