POLINA NIKOLSKAYA and EMILIO PARODI RUSSIAN developers of the Sputnik V vaccine against COVID-19 have applied for domestic approval of a single-dose "light" version, and that trials of it in Russia, the United Arab Emirates and Ghana have already begun. The slimmed-down shot is not expected to be as effective as the original vaccine, said Arsen Kubataev, of the Russian Direct Investment Fund, the sovereign wealth fund marketing the vaccine abroad. But the outlook for it is "optimistic", he said. RDIF has previously suggested the one-shot version of Sputnik V could be a "temporary" solution for countries with high infections…