Human vaccination against leptospirosis is certainly a goal of the research community and would undoubtedly save many thousands of lives each year, but progress has been extremely slow. Currently a vaccine is being tested in Cuba, and results are promising, but it is not yet licensed in the wider world and there are insufficient long-term studies to satisfy us it is safe for widespread use. Human vaccination is a high-profile topic with the public and media, and the potential for side effects in later life, or issues with pregnancy and birth defects, must be ruled out before any medication is issued to the general public on a large scale.
The use of veterinary vaccines in humans is extremely dangerous and must never be attempted!