Mississippi will join 41 other states in requiring a recent Tdap vaccination for all students entering the 7th grade, beginning with the 2012-2013 school year. In order to enter school, all students entering the seventh grade must have documentation from a physician verifying that they have received a recent Tdap vaccination (at age seven or later). This includes new students, current students and transfer students in both public and private schools. Tdap (tetanus, diphtheria and pertussis) vaccination provides protection against whooping cough (pertussis), a highly contagious disease that can be severe or fatal, especially in very young children. Infants who are too young to be vaccinated against pertussis must be protected by ensuring that adolescents and adults around them cannot carry the disease.