Throughout the global effort against Covid-19, Israel’s public health experts have been consistently ahead of their counterparts elsewhere in the world. By securing an early supply deal with Pfizer for its vaccine, sweetened in part by a promise to share data from Israel’s extensive network of health maintenance organizations, they have had an edge in understanding how the vaccine behaves in the real world. They were also willing to act quickly when they saw that data, among other things suggesting to extend the vaccine to younger teenagers and to adopt a Covid passport system to persuade holdouts to get their...