The UK has become the first country in the world to approve a COVID-19 vaccine. On Wednesday, the country's new medicines agency cleared the Pfizer-BioNtech vaccine as safe and effective. The British Government has already bought 40 million doses and says vaccinations of medical staff and the most vulnerable will begin next week. Worldwide testing has shown the vaccine to be 95 percent effective across all age groups. Simon McGregor-Wood has more. For more, we spoke to Doctor Muhammad Munir in the UK. He's a virologist at Lancaster University. #CoronavirusVaccine #Pfizer #BioNTech