Covid-19 vaccine for general use, giving the green light to the Pfizer-BioNTech drug.As authorities in the US and Europe probe other candidates, here is how countries have sped up their approval procedures to face up to the pandemic.Britain: 'rolling reviews'Britain was able to approve the Pfizer vaccine after the independent Medicines and Healthcare products Regulatory Agency (MHRA) gave its all-clear.The MHRA used a "rolling review" process from June to assess the vaccine in record time.Also read: India’s quest to fix its payments puzzleTeams of scientists had worked "around the clock" on different aspects of the safety assessment, often tackling several topics in parallel, MHRA chief June Raine said.Health Secretary Matt Hancock and.