WASHINGTON (Reuters) - The White House said it expected the private sector to take the lead on verification of COVID-19 vaccines, or so-called vaccine passports, and would not issue a federal mandate requiring everyone to obtain a single vaccination credential. The Biden administration was reviewing the issue and would make recommendations, White House press secretary Jen Psaki said on Monday, but she added, “We believe it will be driven by the private sector.” “There are a couple key principles that we are working from. One is that there will be no centralized universal federal vaccinations database, and no federal mandate...