Coronavirus vaccine maker AstraZeneca has been given the all-clear by the UK competition watchdog to go ahead with its $39 billion (£28.2 billion) megadeal to buy U.S. drug company Alexion Pharmaceuticals. The Competition and Markets Authority (CMA) said it had decided not to refer the acquisition for an in-depth investigation, paving the way for the deal to close on July 21. The CMA said in May that it was looking into whether Cambridge-based AstraZeneca’s acquisition of Alexion could harm competition in the UK. AstraZeneca agreed to buy Boston-based Alexion for $175 (£123) a share in December, marking the drug giant’s biggest acquisition, in a move to boost its expertise in immunology and rare diseases. The cash-and-shares deal was approved by shareholders in May and had already been given clearance in 10 countries, including by the U.S. Federal Trade Commission, before the CMA decision. Marc Dunoyer, executive director and chief financial …