Sputnik V vaccine has shown no signs of blood clots â Gamaleya institute Share An analysis of Russia's Covid-19 vaccine, Sputnik V, has revealed that there were no cases of blood clot formation after inoculation, which developers say could be due to its purification technology. Developed by the state-run Gamaleya Research Institute of Epidemiology and Microbiology in Moscow, the Sputnik V viral vector vaccine is similar to those developed by AstraZeneca and Johnson & Johnson (J&J). However, researchers from the Gamaleya institute said in a press release that unlike other vaccines, Sputnik V uses a 4-stage purification technology which could be the reason why there were no cases of cerebral venous sinus thrombosis (CVST) in clinical trials.