There has been some confusion about the use of “5 in 1” vaccines. Ewes do require a booster every year but only to provide protection for the lambs via their colostrum. It is important that they receive the initial two-shot regime (4-6 weeks apart) prior to the ongoing annual booster vaccination. So if the vaccination status is unknown, it is best to give a sensitiser dose and then a booster 4 weeks later followed by an annual booster in subsequent years. The booster should be given 2-4 weeks pre-lambing to give maximum protection to the lambs for the first 12 weeks of life. The replacement lambs will require a sensitiser at 12-16 weeks of age when the protection they received from the colostrum is beginning to weaken, and a booster 4 weeks later. Lambs born to ewes that did not receive an annual booster pre-lamb or if the timing of vaccination was incorrect, should receive lamb vaccine at docking (around 2-4 weeks). Lamb vaccine is not a “5 in 1” vaccine and is designed to give 2-3 weeks protection against tetanus following docking and to give a sensitiser (first) dose against Pulpy Kidney. Therefore, in order to adequately protect lambs born to unvaccinated ewes against Clostridial disease, lambs should receive a “5 in 1” sensitiser 4 weeks after the lamb vaccine and then a booster in another 4 weeks (i.e. a lamb vaccine followed by two “5 in 1” vaccines).