The analysis, which drew from hundreds of coronavirus cases in dozens of countries, found that some patients had symptoms for months after diagnosis.
Europe's daily Covid deaths rose by nearly 40% compared with the previous week, the World Health Organization (WHO) has told the BBC.
Levels of protective antibodies in people wane "quite rapidly" after coronavirus infection, say researchers.
The story of India's first "saviour sibling" has made national headlines. It has also raised questions about the ethics of using technology to create a child only to save or cure a sibling in a country with poor regulatory systems. The BBC's Geeta Pandey in Delhi reports.
"I still have nightmares most nights about being completely out of my depth."
The UK is pushing ahead to be the first nation to carry out "human challenge" studies where up to 90 healthy people will be deliberately exposed to Covid.
Stress affects the skin in various ways
Twin girls who were born joined at the head, and separated last year by a team at Great Ormond Street Hospital in London, have returned home to Pakistan.
The UK is pushing ahead to be the first nation to carry out "human challenge" studies where up to 90 healthy people will be deliberately exposed to Covid
Anti-viral drug remdesivir has little to no effect on Covid patients' chances of survival, a study from the World Health Organization (WHO) has found.
