Follow RT on A study published in an American medical journal has shown that Sinopharm’s two jabs are 72.8% and 78.1% effective at preventing symptomatic Covid-19, but says there is insufficient trial data from elderly and vulnerable groups. The study, published in the Journal of the American Medical Association on Wednesday, shows the two Chinese-made shots to be more effective than the World Health Organization (WHO) minimum requirement of 50% efficacy. The study references interim data from phase-3 trials involving 40,832 volunteers from across the UAE, Bahrain, Egypt and Jordan. The published data answers scientists’ calls for greater transparency about the shots that have been administered more than 200 million times around the world.