[vid] Dr. Humphries on tetanus, immunity and epigenetics  Dr. Suzanne Humphries speaks on tetanus, about the disease, how to treat the disease and how to protect from tetanus. She goes through cases of vaccinated groups, that still developed tetanus, which shows that tetanus vaccine is not a guarantee to protect from the disease.  She also goes through the term herd immunity and how epigenetics function and could be affected by vaccination.