Clinical trials showing the single-shot Janssen vaccine as being 66 percent effective at preventing the COVID-19 disease are “very encouraging,” British Prime Minister Boris Johnson said on Friday. “We have secured 30 million doses, and if approved by our medicines regulator we should expect these to be available later this year,” he wrote on Twitter. Janssen is a Belgium-based pharmaceutical firm owned by U.S. company Johnson & Johnson. Among all participants in its phase 3 clinical trial, the Janssen vaccine was 66 percent effective at preventing moderate to severe CCP (Chinese Communist Party) virus cases, 28 days after vaccination, the U.S. parent firm announced on Friday. This came just a day after Novavax announced that its vaccine against the CCP virus was shown to be 89.3 percent effective in a trial in the UK and 60 percent effective in South Africa. Like the Oxford/AstraZeneca jab, which is already being rolled out across the …