An improved protocol for the preparation of a frozen promastigote vaccine for cutaneous leishmaniasis

Until very recently the promastigote vaccine against cutaneous leishmaniasis used in Israel could only be tested simultaneously with its injection into man. A simple protocol for freezing the vaccine in liquid nitrogen is described, which allows prolonged storage of the material in the final container. During storage, tests of biochemical identity, sterility, pyrogenicity and infectivity for animals and cultured cells are carried out. The logistics of transport are discussed. Transfer from -196 to -20°C was deleterious, while storage at -79°C preserved activity for at least a month.