According to a study led by ICMR, coronavirus mutants that are believed to be the reason behind the second wave, were introduced by foreign travellers and transmitted within the country by migrant workers and those attending religious gatherings.
“The early transmissions could be chiefly traced to movements of migrant workers and the holding of religious gatherings. The independent identification of the amino acid mutations observed in the SARS-CoV-2 variants from the early phase samples indicates an evolutionary trend in the current circulating strain that is geared towards host adaptation," Mint quoted the study.
Three variants, i.e. B.1.1.7 lineage, variant of concern (VOC) and B.1.351 lineage have been reported in India. These variants are of concern due to “antigenic drift, increased transmissibility, and immune escape (especially for B.1.351) mechanisms," the ICMR said. Recently, a new lineage (B.1.617) was identified in Indian SARS-CoV-2 sequence, with the E484Q and L452R mutation (commonly known as a double mutant) in the spike protein of SARS-CoV-2, which is considered to have a higher transmission rate.
“The SARS-CoV-2 sequence analyses during the period between January and August 2020 revealed the presence of the E484Q mutation in the spike protein. These sequences were found in Maharashtra in March and July 2020. Another immune escape mutation, the N440K amino acid in the spike protein, was also observed in Telangana, Andhra Pradesh, and Assam from May 2020," according to the study.
ICMR on Thursday also said home usage of Rapid Antigen Tests (RAT) is advisable only on symptomatic individuals and immediate contacts of coronavirus-positive patients confirmed by laboratories.
Issuing a new advisory for home testing, the ICMR said indiscriminate testing is not advisable and should be conducted according to the procedure described by the manufacturer in the user manual.