Mutations

A WHO official weighs in on Covid, vaccines, and mistakes that were made "The biggest collective failing has been that we've underestimated this microbe," the WHO's Mike Ryan says of SARS-CoV-2. Helen Branswell STAT

The Covid-19 pandemic has entered its third year, with no end in sight, and the world is fed up to the gills. A new and even more highly transmissible variant, Omicron, has been scorching through holiday gatherings over the past couple of weeks. People who are thrice vaccinated are among the infected.

The Centers for Disease Control and Prevention is considering adding testing requirements to its new isolation guidelines for asymptomatic Covid-19 patients, Dr. Anthony Fauci said Sunday.

The CDC shortened its isolation recommendations from 10 days to five last week for people who have tested positive for Covid but show no symptoms. Fauci, President Joe Biden's chief medical adviser, said the agency is debating adding to its guidance.