In reality, ivermectin’s role in human medicine effectively began in April 1978 inside the Merck company, several years before the drug emerged on the Animal Health market. The highly potent bioactivity of a fermentation broth of an organism isolated by the Kitasato Institute in Tokyo, which had been sent to Merck’s research laboratories in 1974, was first identified in 1975. The active compounds were identified by the international multidisciplinary collaborative team as the avermectins, with the subsequently-refined ivermectin derivative being designated the optimal compound for development. Merck scientists, under the direction of Dr William Campbell, found that the drug was active against a wide range of parasites of livestock and companion animals.
10) The informed foresight of a Merck researcher, Ms. L.S. Blair, resulted in the discovery that the drug was effective against skin-dwelling microfilariae of
Onchocerca cervicalis in horses. These did not actually cause clinical disease and so the finding was of little commercial ...