Also read: Why Hollywood studios’ romance for Bollywood has prematurely souredSanofi and GSK said the delay in their adjuvanted recombinant protein-based COVID-19 vaccine programme was to "improve immune response in older adults."The vaccine's potential availability had been pushed back "from mid-2021 to Q4 2021," they said in a statement.American pharmaceutical giant Pfizer and its German partner BioNTech have said their vaccine had proven 90 percent effective in preventing Covid-19 infections in ongoing Phase 3 trials involving more than 40,000 people.US experts voted Thursday to recommend granting emergency approval for the Pfizer-BioNTech vaccine, paving the way for America to become the next country to move ahead with mass immunisation.