A Sporozoon ofPhlebotomus Papatasii

Vaccines against leishmaniasis: using controlled human infection models to accelerate development

INTRODUCTION

Leishmaniasis is a neglected tropical disease that is defined by the World Health Organization as vaccine preventable. Although several new candidate vaccines are in development, no vaccine has successfully reached the market for human use. Several species of Leishmania cause human disease and have co-evolved with their respective sand fly vectors. These unique relationships have implications for initiation of infection and vaccine development. An approach to vaccine development for many infectious diseases is the use of controlled human infection models (CHIMs).

AREAS COVERED

We describe the history and recent development of experimental and deliberate infection using Leishmania in humans and the rationale for developing a new sand fly-initiated CHIM to progress leishmaniasis vaccine development. Examples from other infectious diseases are discussed in the context of the development of a new leishmaniasis CHIM. We also reflect upon the manufacture of the challenge agent, practical considerations, safety, ethics, and regulatory issues.

EXPERT OPINION

A new cutaneous Leishmania CHIM is being developed to enable testing of vaccines in the development pipeline. Questions remain about the use of such CHIMs to determine effectiveness of vaccines against visceral leishmaniasis. However, such a CHIM will be invaluable in expediting time to market for vaccines.

Saul Adler, 1895 - 1966

If the seeking of truth for its own sake and the pursuit of knowledge, urged on by a divine curiosity untinged with thought of gain or expediency, are the hall-marks of a scientist, then surely Saul Adler was pure gold. A biographical memoir on Adler would give a false representation of him as man and scientist if written without an account of his family background and close parental ties which had so profound an influence on his character from his earliest years and throughout his life. The social and economic state and the cultural atmosphere in the homes of his grandparents on both sides, as well as the scholarly conditions obtaining in his home life, in spite of the most straitened circumstances, were fundamental influences on Adler’s character. His paternal grandfather was a small corn merchant always on the edge of want, while his maternal grandfather was a shopkeeper only fractionally better off. Adler’s father was born in Russia at Kletzk and his mother at Karelitz, where Saul Adler was born. His father studied at various Talmudical colleges in Russia and received his rabbinical diploma. The home was full of Hebrew books, not only the Talmud but talmudic histories and commentaries on the Bible as well as modern Hebrew literature—poetry, novels and periodicals. His father’s consuming love of the Hebrew language, which he knew with an intimacy which scholarship alone would not have accounted for, was certainly transmitted to his son.