Two-thirds of Omicron COVID cases are reinfections: English study
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A new study has found that a vast majority of people recently infected with Omicron variant say they had already had COVID previously - CNBC.
Imperial College Londonâs React study analyzed 100,607 PCR test results from across England. Swabs were collected between Jan. 5 and Jan. 20.
Two-thirds of the 3,582 participants who tested positive in January reported they had already tested positive for COVID in the past. 
A further 7.5% of infected participants said they suspected they had previously had the virus, but had not confirmed this with a test. 
Past infection was associated with high risk of reinfection with Omicron. The study found that 99% of sequenced positive swabs came from people infected with Omicron variant, with only 1% of infections being caused by Delta variant.
The Imperial College study also found that 0.4% of positive tests were caused by the BA.2 omicron sublineage, the most dominant, trends in India.
Vaccine makers: Pfizer (NYSE:PFE), BioNTech (NASDAQ:BNTX), Moderna (NASDAQ:MRNA), Johnson & Johnson (NYSE:JNJ), AstraZeneca (NASDAQ:AZN), and Novavax (NASDAQ:NVAX).
Recently, a U.S. study suggested that Omicron variant is less likely to result in hospitalizations than Delta.