Scientific experts at the World Health Organization warned on Friday that a new coronavirus variant discovered in southern Africa was a “variant of concern,” the most serious category the agency uses for such tracking.

The designation, announced after an emergency meeting of the health body, is reserved for dangerous variants that may spread quickly, cause severe disease or decrease the effectiveness of vaccines or treatments. The last coronavirus variant to receive this label was Delta, which took off this summer and now accounts for virtually all Covid cases in the United States.

The W.H.O. said the new version, named Omicron, carries a number of genetic mutations that may allow it to spread quickly, perhaps even among the vaccinated.

Continue reading “New Virus Variant Stokes Concern but Vaccines Still Likely to Work” →

A scientist who has pored over public accounts of early Covid-19 cases in China reported on Thursday that an influential World Health Organization inquiry had most likely gotten the early chronology of the pandemic wrong. The new analysis suggests that the first known patient sickened with the coronavirus was a vendor in a large Wuhan animal market, not an accountant who lived many miles from it.

The report, published on Thursday in the prestigious journal Science, will revive, though certainly not settle, the debate over whether the pandemic started with a spillover from wildlife sold at the market, a leak from a Wuhan virology lab or some other way. The search for the origins of the greatest public health catastrophe in a century has fueled geopolitical battles, with few new facts emerging in recent months to resolve the question.

Continue reading “First Known Covid Case Was Vendor at Wuhan Market, Scientist Says” →

Novavax, a Maryland-based company that received $1.75 billion from the United States government to develop a protein-based Covid-19 vaccine, announced Monday it had won emergency authorization for its vaccine in Indonesia.

After months of production delays, this is the first authorization for Novavax and its manufacturing partner, the Serum Institute of India. They have also applied for clearance in India and the Philippines, and Novavax has applied on its own to other countries, including Britain and Canada.

Continue reading “The Novavax vaccine, backed by Operation Warp Speed, has won its first authorization — in Indonesia.” →

The National Institutes of Health said on Wednesday that a nonprofit group under fire from some congressional Republicans for its research collaborations in China had failed to promptly report findings from studies on how well bat coronaviruses grow in mice.

In a letter to Representative James Comer, Republican of Kentucky, the N.I.H. said that the group, EcoHealth Alliance, had five days to submit all unpublished data from work conducted under a multiyear grant it was given in 2014 for the research. The organization’s grant was canceled in 2020 under President Donald J. Trump’s administration during his feud with China over the origins of the coronavirus.

Continue reading “Bat Research Group Failed to Submit Virus Studies Promptly, N.I.H. Says” →

The Food and Drug Administration seems likely to allow Americans to switch vaccines when choosing a Covid-19 booster shot. That authorization, which could come this week, is the latest development in a long-running debate over whether a mix-and-match strategy helps protect people from the coronavirus.

Here are answers to some common questions about mixing and matching booster shots.

Continue reading “Mix-and-Match Covid Boosters: Why They Just Might Work” →