Omicron may cause milder symptoms. But experts aren’t breathing easy yet.

Amid the global concern over a new coronavirus strain has been one piece of hopeful news: Those infected with the omicron variant appear to have “very mild” symptoms, according to the South African doctor who first spotted the variant.

Dr. Angelique Coetzee told the BBC that neither she nor her colleagues had admitted anyone who had the strain to the hospital so far. Her patients had experienced extreme fatigue but no loss of taste or smell, which are often telltale symptoms of Covid-19, she said.

The early reports are encouraging, epidemiologists and other experts said. 

But they cautioned that there is too little data to draw any conclusions yet. Their bigger concern, they said, is how quickly the omicron variant, with its high number of mutations, might spread and how it will match up against vaccines.

“I don’t think we know anything about the virulence. What we’re worried more about is the transmissibility and the immune-evasion capabilities,” said Dr. Amesh Adalja, an infectious disease doctor who is a senior scholar at the Johns Hopkins Center for Health Security.

Adalja said he suspected that vaccination would still provide strong protection against severe disease, while unvaccinated people who have natural immunity from previous Covid infections could be at even higher risk for getting the virus again. ...