There are many diseases for which sheep and goats can be vaccinated, but there is only one universally-recommended vaccine, and it is for the clostridial diseases that commonly affect small ruminants.
Clostridial diseases are fatal diseases that strike ruminant livestock suddenly, often causing death before any clinical signs are seen. Clostridia (bacteria) are widespread in the environment. They are normally found in the soil and feces. They are also present in the digestive tract and tissues of healthy animals. For these reasons, vaccination is the best way to prevent disease outbreaks.
Two clostridial vaccines are commonly used in sheep and goats: a 3-way vaccine called CDT; and an 8-way vaccine. CDT protects healthy sheep and goats against clostridium perfringens type C and D (overeating disease) and clostridium tetani (tetanus). The 8-way vaccine protects against these same diseases, plus several additional clostridial diseases, including blackleg. The 3-way vaccine is probably all that’s needed on most sheep and goat farms.