Portuguese scientists said they had developed an experimental vaccine against tooth decay which was successful in laboratory tests on rats and could pave the way for a version that works for humans. “What we found is that the animals which were vaccinated with this protein developed much smaller lesions than the control group which had not been vaccinated,” said Paula Ferreira, one of three Oporto University researchers who worked on the vaccine."There is still a long road to travel (for a human version). Before that experimental models which are closer to man need to be tested, namely in monkeys, and for that financing is needed,” she told Lisbon-based TSF radio.Rats were used to test the experimental vaccine because the type of tooth decay they develop is similar to that which occurs in humans, she added.The three scientists have already patented the vaccine in Portugal and are working on doing so in the United States where they are also seeking funding to further their research, Ferreira said.