Geneva, Feb 10 (IANS): The World Health Organization (WHO) has announced that the Covid-19 variant B.1.1.7, which was first identified in the UK on September 20, has been reported in 86 countries.

In its weekly epidemiological update, WHO says the variant B.1.1.7 has shown an increase in transmissibility, and some evidence of increase in disease severity based on preliminary findings.

As of February 7, an additional six countries have reported cases of this variant.

In the UK, for example, Covid-19 test samples of this strain increased from 63 per cent in the week of December 14 to 90 per cent in the week of January 18, the WHO said on Tuesday.

Additionally, WHO has also been monitoring two additional Covid-19 strains that are actively spreading: B.1.351, initially seen in South Africa and the P.1 strain that was first identified in Brazil, CNN reported.

As of February 7, the B.1.351 strain has been reported in 44 countries, while the P.1 strain has been reported in 15 nations, WHO says.

Scientists are not surprised to see the Covid-19 virus changing and evolving but they fear that a variant could mutate to the point that it causes more severe disease, bypasses the ability of tests to detect it or evades the protection provided by vaccination, the report said.