The administration has struggled to launch a $650 million program it announced in February to set up regional Covid-19 testing hubs for schools and facilities like homeless shelters. Federal officials had hoped to have the first hub open and coordinating 150,000 tests per week by late April, but have not yet awarded any contracts. And while the White House announced in March that it would spend $10 billion in stimulus money to support testing programs in schools across the country, planning has been left largely to states, cities and local school districts. The CDC began distributing the money to state and local health departments in early April, but it is not clear how much schools have spent in the waning months of the 2020-2021 school year. Now, with vaccination slowing the virus’s spread, some schools are reopening without the kind of widespread Covid-19 screening that Biden once envisioned as crucial.