The first assessment of the Brazilian variant of COVID-19, newly identified in the UK, shows it may spread more easily – and evade the immune system.
Scientists from Brazil and the UK estimate the variant, known as P1, is 1.4 to 2.2 times more transmissible than previous versions of coronavirus circulating in Manaus, the Amazon city where it originated.
It is also able to evade between 25% and 61% of protective immunity from previous infection, according researchers at Imperial College London and the University of Sao Paulo.
The study has not been peer reviewed.
Almost 70% of the Manaus population had immunity from the first wave of COVID infections last spring, yet a surge of re-infections at the start of this year led to hospitals in the city being overwhelmed.
Six UK cases of the P1 variant have been identified in people who recently returned from Brazil.
Three cases were identified in Scotland, with another two in South Gloucestershire in England.
And one case has yet to be traced.
Professor Sharon Peacock, who heads the COG-UK, which analyses the genetic make-up of variants, warned that the findings should not be generalised to other cities.
She said the study was “excellent evidence of the biological properties”, but added it was not clear “how it will pan out” in the UK.