LONDON, United Kingdom (AFP) — Britain on Friday approved the use of a fourth Covid vaccine, hoping to boost a countrywide inoculation drive to allow its economy to reopen fully despite concerns about a new variant. The Medicines and Healthcare products Regulatory Agency (MHRA) approved the single-shot Johnson & Johnson jab, after previously backing the Pfizer, AstraZeneca and Moderna shots. Prime Minister Boris Johnson called it “very welcome news and another boost to our hugely […]