A new polio vaccine offers superior immunization and is raising hopes of a total eradication of the disease, according to a study published on Tuesday by British medical journal The Lancet.

There are three types of the polio virus, and while type 2 has been almost entirely eradicated since mass vaccinations began in 1988, types 1 and 3 remain a global health threat.

Scientists have shown for the first time that it may be possible to replace a human hip or knee with a joint grown naturally inside the body using the patient's stem cells.

In experiments on rabbits, the researchers coaxed the animals' stem cells to rebuild the bone and cartilage of a missing leg joint, according to a study published on Thursday.