New Delhi: SARS-CoV-2 variant B.188.8.131.52, which was first identified in Brazil last year, could cause more severe disease than the original B.1 variant that spread from Wuhan, according to researchers from the Indian Council of Medical Research (ICMR) in New Delhi and the National Institute of Virology in Pune who came out with the observation after a study of the virus in Syrian hamsters.
The B.184.108.40.206, however, has so far had very less prevalence worldwide, with less than 0.5 per cent of the viral samples detected worldwide showing this strain.
In a study that is yet to be peer reviewed, researchers said they had isolated the samples as part of genomic surveillance ongoing in India, considering the potential threat from emerging SARS-CoV-2 variants and the rising Covid-19 cases.
The team isolated samples of the variant, also known as P.2, from two international travellers who had tested positive for Covid-19. The two were asymptomatic. One of them had travelled from the UK in December 2020, while the other came from Brazil in January this year.
The two are the only samples of this variant isolated by Indian labs so far. No sample sequenced from India so far has been of this variant.
What the study found
The team then studied Syrian hamsters that were infected with the P.2 variant, and compared it to hamsters infected with the B.1.
The team found that the B.220.127.116.11 variant induced body weight loss, viral replication in the respiratory tract, lung lesions and caused severe lung disease in the hamsters compared to the B.1 variant.
The team also found that higher levels of antibodies were needed to neutralise the B.18.104.22.168 variant as compared to the B.1 variant.
“The findings of increased disease severity and neutralisation reduction is of great concern and point towards the need for screening the vaccines for efficacy,” the researchers wrote in their study.
The B.1 variant is defined by one mutation of concern in spike protein, i.e, D614G.
During January 2021, lineage P.1, which included the mutations N501Y, E484K and K417N on the spike protein, was identified in travellers from Brazil in Japan. While the properties of this variant are still unknown, this variant may have facilitated the re-infections in Manaus city of Brazil, the researchers said.
The P.2 variant was also reported from Brazil, which has E484K mutation but not the N501Y and K417N in the spike protein.