Infections caused by the Omicron variant of the coronavirus do not appear to be less severe than infections from Delta, according to early data from the UK.

Researchers at Imperial College London compared 11,329 people with confirmed or likely Omicron infections with nearly 200,000 people infected with other variants. So far, according to a report issued ahead of peer review and updated on Monday, they see "no evidence of Omicron having lower severity than Delta, judged by either the proportion of people testing positive who report symptoms, or by the proportion of cases seeking hospital care after infection."

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Sperm quality is impaired for months for some people after recovery from COVID-19, researchers have found.

The semen itself was not infectious, the researchers found. But among 35 men who provided samples within a month after recovery from symptomatic infection, reductions in sperm motility were evident in 60% and sperm counts were reduced in 37%. As reported on Monday in Fertility and Sterility, semen samples were obtained from 120 Belgian men with an average age of 35 years, at an average of 52 days after their COVID-19 symptoms had resolved. Among 51 men tested between one and two months after recovery, 37% had reduced sperm motility and 29% had low sperm counts. Among 34 men who provided semen samples at least two months after recovery, sperm motility was impaired in 28% and sperm counts were low in 6%. The severity of COVID-19 infection was not correlated with sperm characteristics.

https://www.reuters.com/business/healthcare-pharmaceuticals/omicron-infections-appear-no-less-severe-than-delta-covid-19-lowers-sperm-count-2021-12-20/

Covid infections normally only involve one mutant strain, but in extremely rare cases two can strike at the same time.

If these also infect the same cell, they may be able to swap DNA and combine to make a new version of the virus.

Dr Paul Burton, the vaccine maker's chief medical officer, warned the high numbers of Delta and Omicron cases currently circulating in Britain made this more likely.

He told MPs on the Science and Technology Committee that it was 'certainly' possible they could swap genes and trigger an even more dangerous variant.

https://www.dailymail.co.uk/news/article-10309153/Risk-DUAL-infection-Omicron-Delta-create-new-super-mutant-variant.html