Hi, Thanks for the query. Tetanus vaccine works for 10 years. It stimulates your immunity against tetanus and this immunity stays for 10 years. However, if you are at the risk of exposure to tetanus infection, as in the case of doctors, nurses, any medical personnel, person working in a place where getting injured is common then it is advisable to take vaccine every six months. This is called booster dose. It means immunity will be there because of previous vaccination but to boost that immunity, we take tetanus vaccine every 6 months. If you are not in that risk category, then there is no need to take this vaccine every 6 months. However, if you get any cut wound, open wound, prick by a needle etc and if the last vaccination duration is more than 6 months, then only you should take this vaccine to boost your immunity against tetanus. Hope this clears your doubt. Regards, Dr. Prathap