LONDON (AP) — The U.K. has became the first country in the world to start using the COVID-19 vaccine developed by Oxford University and drugmaker AstraZeneca. It is ramping up a nationwide vaccination program as rising infection rates are putting an unprecedented strain on British hospitals. The U.K. is in the midst of an acute outbreak, recording more than 50,000 new coronavirus infections a day over the past six days. Prime Minister Boris Johnson says tougher restrictions will be announced soon as Britain struggles to control a new, more contagious virus variant.