Lepto Vaccination Side Effects. However, please keep in mind that the leptospirosis vaccine is most commonly associated with. Granulomas, or hard tissue formations may occur at the site of vaccination.

How long do lepto vaccine side effects last? Reactions to the leptospirosis vaccine usually take the form of lethargy for a few days and possibly loss of appetite. There have been reports of reactions to the vaccine that vary from minor to severe.