GENEVA (Reuters) - EU regulators have reached out to their British counterparts to share information from their review of Pfizer Inc’s COVID-19 vaccine, a WHO medical expert said on Thursday. Britain approved the vaccine on Wednesday, jumping ahead of the rest of the world in the race to begin the most crucial mass inoculation programme in history. Prime Minister Boris Johnson touted the green light from Britain’s medicine authority as a global win though he recognised the logistical challenges of vaccinating an entire country of 67 million. U.S. and EU regulators are sifting through the same Pfizer vaccine trial data, but have yet to give their approval. Reporting by Stephanie Nebehay and John Miller; Writing by Nick Macfie; Editing by Alex Richardson and Jon Boyle