Compared to people infected with less contagious coronavirus variants, those infected with the variant identified in the UK, known as B.1.1.7, are more likely infect their household members, according to new data.
During three weeks in February, researchers in Ontario, Canada, monitored people living with a COVID-19 patient in more than 2,500 roughly-comparable private households.
During the two weeks after patients were diagnosed, the so-called secondary attack rate – the rate at which infections occurred among household members – was 31% higher when the patient was infected with the B.1.1.7 virus variant than when COVID-19 was caused by a less worrisome variant.
When the original infected person never developed symptoms, the secondary attack rate was 91% higher with B.1.1.7, the researchers reported on medRxiv ahead of peer review.
And when the original patient had no symptoms at first, and then became ill, the rate at which household members became infected was more than 200% higher when the patient carried the B.1.1.7 variant.
Since emerging in the UK, B.1.1.7 has spread to more than 100 other countries. It has now become the dominant coronavirus variant in the United States, according to the U.S. Centers for Disease Control and Prevention.
Photo: EPA-EFE/Gustavo Amador