BERLIN—German health officials agreed Tuesday to restrict the use of AstraZeneca’s coronavirus vaccine in people under 60, amid fresh concern over unusual blood clots reported in a number of those who received the shots. Health Minister Jens Spahn and state officials agreed unanimously to only give the vaccine to people aged 60 or older, unless they belong to a high-risk category for serious illness from COVID-19 and have agreed with their doctor to take the vaccine despite the small risk of a serious side-effect. The move follows the recommendations of Germany’s independent vaccine expert panel and comes after the country’s medical regulator released new data showing a rise in reported cases of an unusual form of blood clot in the head—known as sinus vein thrombosis—in recent recipients of the AstraZeneca vaccine. The news is a further blow to the vaccine. It comes less than two weeks after the EU drug …