jim bittermann, cnn, just outside paris. there's new scrutiny of federal u.s. covid guidance as more states move forward with lifting mask mandates. new infections are declining across the country, as the omicron wave subsides. well, that drop has led to a number of states relaxing measures towards a new normal. and even retailers are making the change. walmart is lifting its mask mandate, effective immediately for fully vaccinated employees. the chain also said that it's ending the required daily health screenings for employees by the end of the month, except for those working in states where it's still required. now, th ethe evolving guidance drawn attentions to federal recommendations. plus, the world health organization warns that the pandemic isn't over. >> we have seen the virus evolve, mutate, and in fact, the kromicron variant was detected