How likely omicron is to cause reinfection, whether omicron is milder than other variants, and more.

How likely is the omicron variant to cause reinfection? Here's what a new study found. (Monday, Dec. 6)

A new study from South Africa suggests the omicron variant is much more likely than other variants to reinfect those who previously had Covid-19. Here's what experts say the finding could mean for both natural and vaccine-induced immunity against the coronavirus.

Is omicron actually milder than other variants? Here's what we know so far. (Tuesday, Dec. 7)

Early data from South Africa suggests that, while the omicron variant spreads remarkably quickly, it may cause relatively mild Covid-19 symptoms. But public health experts warn omicron may appear mild only because—so far—it's spreading in populations that already have widespread immunity from prior coronavirus waves.

Do vaccines protect against omicron? What early evidence shows. (Wednesday, Dec. 8)

Three new laboratory studies show troubling signs that two doses of the Pfizer-BioNTech coronavirus vaccine may not fully protect against the omicron variant. But the research also suggests that three doses may provide much better protection.

The 149 best hospitals, according to Leapfrog (Thursday, Dec. 9)

The Leapfrog Group on Monday released its 2021 Top Hospitals list, recognizing 149 hospitals for excellence in hospital quality, patient safety, and efficiency—and 115 hospitals on the list are Advisory Board members.

Omicron evades many vaccine antibodies. (But that doesn't mean vaccines won't work.) (Friday, Dec. 10)

Early data suggests the omicron variant may be better able to evade vaccine antibodies than other variants. But several infectious disease experts caution that these findings don't provide a complete picture of omicron's ability to escape vaccine-induced immunity, and that vaccinated people will likely remain protected against severe outcomes.