I do not have a scientific background and have only a basic understanding of leishmaniasis but I do have a question as my curiosity has gotten the better of me. I finished reading a book that mentioned they attempted to make a vaccine with dead parasites, but that it didn't work and they were not sure why. They also mentioned that leishmaniasis parasites have sex in the sand fly but use mitosis in humans. Provided this is true would it be possible to genetically alter the parasite so that they could still mate but could no longer divide themselves in the human body? In doing so, the parasite could still be 'manufactured' and if given to humans in order to get a response from the immune system to create an unfair fight (the immune system could fight off the injected leish and the leish could not reproduce). I'm not sure of the life cycle of leish but would multiple exposures of leish that couldn't replicate themselves give humans a certain level of immunity? Thank you for your time. I hope the question is not overly stupid, as it may be impossible to alter genetics at this time. But if it was possible and I believe there are advances in this area would such a 'vaccine' work. If it is, please disregard this email. Cheers!