The key to preventing cavities in teeth lies in controlling an acid-secreting bacterium known as Streptococcus mutans that lives in the mouth. Researchers at the Harvard School of Dental Medicine believe they can prevent cavities for life by vaccinating babies against S. mutans. “If we can get the babies immunized before the bacteria have had a chance to colonize, then we can offer protection for perhaps the rest of their lives,” said Daniel Smith, HSDM associate clinical professor of oral biology and pathophysiology. Smith and Martin Taubman, professor of oral biology at HSDM, have worked to develop a vaccine that is effective and easily administered. Part of their strategy is to deliver the vaccine as a nasal spray, which is likely to be better tolerated by small infants than are injections. They hope to test the vaccine in clinical trials soon.