The differences between omicron and delta variant symptoms were analyzed as part of a COVD-19 infection survey.
The delta variant has been identified in at least 180 countries, according to the World Health Organization.
How effective are our vaccines against the Delta variant - and when should you get a booster shot? Dr. Francis Collins, director of the National Institutes of Health is answering some questions about the COVID-19 vaccine - and the breakthrough cases that seem to be happening more frequently.
NIH scientists discovered a new COVID-19 test technique that may reduce test time and cost while increasing efficiency.