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Leptospirosis Vaccination - What if It's Given Late?

    • 344 posts
    April 16, 2018 10:21 AM EDT

    This question was asked during the webinar on "The Increasing Threat of Canine Leptospirosis ...":

    AHAA guidelines say if Lepto annual vaccination is late, vaccine should be boostered. How late is late, weeks, months?

    Answer provided by Dr. Jason Stull & Dr. Michelle Evason:

    The initial 2 doses of leptospirosis vaccination should be administered 2 to 4 weeks apart (timing may vary with vaccine product used so be sure to refer to the manufacturer’s instructions).  Regarding the MAXIMUM interval between doses during the initial series, the 2017 AAHA guidelines state, “Published studies are not available. It is generally recommended to restart the 2-dose series when the vaccination interval between the first and second dose exceeds 6 weeks.” 


    Following the initial series (i.e., 2 doses 2-4 weeks apart) of the currently licensed vaccines, a booster is to be given of a single dose every 12 months. Regarding the MAXIMUM interval between boosters after the initial series, the 2017 AAHA guidelines state, “Sufficient data does not exist to assess the immune response to a single dose of vaccine in dogs that have not received a booster vaccination within 1 year since the previous dose. However, if more than 18 months has elapsed since the previous dose, it is reasonable to administer 2 doses 2 to 4 weeks apart.”

    Individuals should always contact the vaccine manufacturer to confirm the above details.