Sydney Cohen obituary

My father, Sydney Cohen, a scientist with a deep love of nature, who has died aged 95, developed from his South African education and wide travels in Africa a determination to vanquish malaria, the continent's scourge.

His pursuit of a vaccine led, in 1961, to a landmark paper in Nature, co-written with Ian McGregor, that found that immunoglobulin from immune Gambian adults had an anti-parasitic effect when administered to infected children. While variation in parasites has precluded to this day an effective vaccine against all strains of malaria, Sydney was one of the first to show that successful vaccination was possible, using forms of the parasite that live in the blood.