Leishmune, the first licensed
vaccine for prophylaxis against canine
visceral leishmaniasis (CVL) and is also immunotherapeutic when used with double
saponin adjuvant concentration. The Leishmune therapeutic
vaccine was assessed for
immunotherapy (IT) in 31 infected dogs and for immunochemotherapy (ICT) in combination with
allopurinol or amphotericinB/
allopurinol, in 35 dogs. Compared to infected untreated control dogs, at month 3, both treatments increased the proportion of dogs showing intradermal response to Leishmania
antigen to a similar extent (from 8 to 67%, in the IT and to 76%, in the ICT groups), and conversely reduced from 100 to 38% (IT) and to 18% (ICT) the proportion of symptomatic cases, from 54 to 12% (IT) and to 15% (ICT) the proportion of parasite evidence in lymph nodes and from 48 to 19% (IT) and 12% (ICT) the proportion of deaths, indicating that the
immunotherapy with enriched-Leishmune
vaccine promotes the control of the clinical and parasitological signs of CVL rendering most dogs asymptomatic although PCR positive. By month 8, negative lymph node PCR results were obtained in 80% of the ICT-treated dogs, but only in 33% of the IT group (p=0.0253), suggesting that the combination of additional
chemotherapy with Leishmune-enriched
saponin vaccination abolished, not only the symptoms but also the
latent infection condition, curing the dogs. The animals were followed up until 4.5 years after the beginning of the experiment and, compared to the untreated control group at month 3 (12/25 dogs; 48%), a decrease in the rate of CVL deaths was only seen after ICT treatment (7/35 dogs; 20%; 0.0273) but not after IT treatment (10/31 dogs; 32%; p=0.278), pointing out an additional advantage of the ICT treatment with the enriched-Leishmune in the control and cure of CVL.