Kerala's latest COVID-19 surge possibly linked to UK variant: INSACOG data

The UK variant which constituted just 1.06 percent cases on January 20 and 3.8 percent on March 20, now constitute 30.48 percent

Kerala’s surge of COVID-19 cases in recent weeks is possibly linked to the UK variant B.1.17.

The latest data from genomic surveillance of COVID-19 positive cases in Kerala by Indian SARS-CoV-2 Genomics Consortium (INSACOG) found that 30.5 percent of the COVID-19 positive samples sequenced from the state were caused by the UK variant B.1.17.

The UK variant which constituted just 1.06 percent cases on January 20 and 3.8 percent on March 20, now constitute 30.48 percent, as per data from April 25. In just one month, the UK variant has grown almost 10 times. By mid-March, Kerala started seeing huge dip in new cases. But, things have, however, reversed.

The state is now seeing a surge in COVID-19 cases. The state reported over 20,000 cases for the fifth consecutive day. Despite a heavy load of cases - the state managed to keep the mortality rate at 0.4 percent, one of the lowest in the country.

Kerala, so far, has reported 1.43 million cases and 5,138 deaths. There are about 2,33,140 active cases.

The UK variant is found in 75 percent of the COVID-19 cases sampled in Kannur, 66.67 percent in Kasaragod, 59.38 percent in Malappuram, 50.65 percent in Ernakulam and 50 percent in Wayanad.

The B.1.1.7 (501.V1) variant emerged in the UK in late 2020, associated with high infectivity. The variant is now found in over 100 countries and associated with the major surge in COVID-19 cases in the UK and Europe in recent months.

INSACOG hasn't provided the number of samples it has sequenced from Kerala, but it has a mandate to sequence at least 5 percent of COVID-19 positive cases from India and also travellers who tested positive on arrival to India.

The other two variants of concern - the South African variant B.1.351 and Indian double mutant B.1.617, which were non existent till March 20, have been found in 4.38 percent (B.1.351) and 6.67 percent (B.1.617) of the sequenced COVID-19 positive samples.

B.1.351 (501.V2) variant emerged in South Africa is also associated with increased infectivity and associated with E484K mutation with additional immune escape property. This variant has been associated with resistance to panels of convalescent plasma as well as decreased efficacy of specific vaccines.

The UK variant is found in 75 percent of the cases sampled in Kannur

B.1.617 - a new lineage of SARS-CoV-2 prevalent in the state of Maharashtra - is now found in over 10 states in India. Characterised by two mutations, E484Q and L452R with functional consequences in the spike protein, apart from four additional variants which define the lineage.

L452R is associated with increased infectivity and resistance to some monoclonal antibodies while E484Q is associated with immune escape and resistance to polyclonal sera.