CAB is correct -- there are two variations of the product line. One treats the symptoms (Anti-Toxon) where as the other is a vaccine -- (Toxoid)
For every one who is interested or may not know -- here is what I feel needs done on EVERY calf.
Birth -- ASAP - 2ml of Alpha-7 -- this is given under the skin sub-q and is formulated for new borns -- it works, it gives you about 30 days of good immunity to start those calves good.
30 days -- Vision-7 or Vision-8 -- this is also a vaccine, but of a different carrier base, also given sub-q.
Word of warning here folks -- Clostridium vaccines are - by nature -- very irritating. If the bottle says Sub-Q --you MUST make sure it goes under the skin and does not go into any muscle or skin tissues. If you do, you will almost always have a very LARGE abcese to deal with later. It swells up pretty big too.
Tent the skin behind the front leg low on the rib cage, and give it there. Make sure you are in the air space under the skin, if it pushes out easy -- you are good, if it gives you any resistence, repostition until you are not in the tissues.
If you have one that gets the symptoms, treat as I described above, you have NO time to lose either.
Not that I know every tihng there is to know, but this is one topic I can tell you about with no hesitation, it is a deadly bug, and it works fast to kill your calves! It always better to prevent, than to treat!
Good luck -- another year -- Terry