Health organizations worldwide monitoring Omicron variant with over 30 protein spike mutations; expert says it is too early to know its impact

Combo shots modified to better protect against Omicron strains while still targeting earlier versions of the virus

Dr. Rochelle Walensky says public health body 'fell short' in dealing with coronavirus, proposing restructuring plan aimed at making CDC more nimble and improving communication

Health Ministry says investigation launched to discover where 36-year-old resident of northern Israel came into contact with extremely rare, but often fatal organism

Move paves way for more decisive action against virus, amid criticism against Biden administration over lack of access to vaccines

Requirement on airplanes, subways, trains, buses, taxis no longer in effect, with TSA subsequently announcing it won't enforce directive at airports either

Official says CDC is developing a 'revised policy framework' for when face coverings should be required on transit systems, but requirement to stay until at least mid-April

Regulators urging drugmaker to apply for emergency authorization of 2-dose regimen of shot for kids aged 6 months to 5 years old while awaiting data on 3-dose course

Research finds third dose at least 90% effective at preventing hospitalizations for COVID-19, during both the Delta and Omicron waves

'Pediatric hospitalizations are at their highest rate compared to any prior point in the pandemic,' says CDC chief, but notes they are still lower than other age groups