More food for thought, an article about Lepto, including vaccine, from the MSPCA Angell Animal Medical Center in Boston, a renowed 24-Hr hospital seeing 65,000 patients a year.
Note where it says this (and why I don't vaccinate).
"Vaccination against Leptospira is only available for the serovars canicola, grippotyphosa, pomona and icterohaemorragiae. Most recent outbreaks of the disease involve serovars for which vaccination does not exist."
Leptospirosis: What is it, and how can I protect my dog?