A new study in the New England Journal of Medicine questions the cost-effectiveness of Gardasil in older women, saying that the payback is reduced by their increased exposure to the virus that causes cervical cancer. But the team of researchers from Harvard School of Public Health also confirmed that the vaccine is cost effective among pre-adolescent girls because of their reduced exposure to the virus. Merck, which makes the vaccine and markets it around the world, quickly disputed the study, saying that its own economic models indicate that the vaccine provides a real payback when used for women. Report