A series of recent studies suggested that the Omicron variant is less severe than previous ones because it largely spares the lungs. Research conducted on mice and hamsters determined that Omicron’s infections were mostly confined to the nose, throat and windpipe. (The New York Times)

A law banning many surprise medical bills went into effect on the first day of the new year. Additional out-of-network bills are now prohibited for emergency care at hospitals and for transport via air ambulances, though ground ambulances are not included in the new law. (Axios)

Israel has launched a second-booster program, offering a fourth vaccine shot to all residents over the age of 60. Epidemiologists remain split on the necessity of a fourth dose. (The Washington Post)

As the Omicron surge continues, the Food and Drug Administration has expanded its authorization of Pfizer booster shots to 12- to 15-year-olds. The Centers for Disease Control and Prevention is expected to issue its recommendation later in the week. (AP)

A top World Health Organization official said he was “disappointed, not surprised” that the pandemic remains in full swing. “The biggest collective failing has been that we’ve underestimated this microbe. We’ve always made judgments assuming the best-case scenario,” said Mike Ryan, head of the WHO’s health emergencies program. (STAT)