Health experts in India have alerted the Centre against the siblings of the delta variant of Covid-19 that are fast spreading across the world. The concern is centered mostly on the possibility of a cocktail of new variants with the normalization of international travel. The variants of concern include B.1.617.3, B.1.1.318, which itself has 14 mutations, Lambda (C.37) and Kappa (B.1.617.1).
The Lambda variant has been under investigation since June 23 and the Kappa variant has been found to be much less infectious than Delta or Delta-plus.
Dr Vighnesh Naidu Y, consultant physician at Yashoda Hospitals in Hyderabad, told The Times of India, “Viruses tend to mutate as they multiply, and mutations are tiny errors in the original genetic makeup of the organism. As these mutate, they change the ability of the virus to infect in terms of faster rate of transmission, increased virulence and their ability to evade our immune response.”
Meanwhile, Lambda variant is being strictly monitored by the Public Health England (PHE) since it spread to other countries.
The Delta variant has about 15-17 mutations and was first reported in October last year, and it was responsible for more than 60 per cent of cases in Maharashtra in February. It has spread to 80 countries, ICMR Director General Balram Bhargava said. The B.1.617 strain has three subtypes B.1.617.1, B.1.617.2 and B.1.617.3 — and B.1.617.2 (Delta variant) has been classified as a variant of concern and it has increased transmissibility, stronger binding to receptors of lung cells, potential reduction in monoclonal antibody response and potential post-vaccination immune escape, he said.
The B.1.617.2 Plus or Delta Plus variant, detected in different parts of India, characterisation of which are ongoing (three mutations), Bhargava said. There are 16 countries where more than 25 per cent of cases of Delta variant have been found, he said. These are Australia, Bahrain, Bangladesh, India, Indonesia, Israel, Japan, Kenya, Myanmar, Peru, Portugal, Russia, Singapore, South Korea, United Kingdom, United States of America.
Vaccines Covishield and Covaxin work against SARS-CoV-2 variants Alpha, Beta, Gamma and Delta, while effectiveness tests against the Delta Plus variant is ongoing, the government said on Friday.
There are four variants of concern of the coronavirus disease — Alpha, Beta, Gamma and Delta — with Delta Plus being a sub-lineage of the Delta variant which is also a variant of concern. Addressing a press conference, Bhargava said reduction of neutralisation capabilities of vaccine with different variants, which is based on global literature, shows that Covaxin does not change with the Alpha variant at all and so it is same as it is with the standard strain.
“Covishield reduces slightly with Alpha, by 2.5 times. For the Delta variant, Covaxin is effective but antibody response is slightly reduced to three-fold reduction, and for Covishield, it is two-fold reduction, while in Pfizer and Moderna it is seven-fold reduction," he said. “However, Covishield and Covaxin work against the variants of SARS-CoV-2- Alpha, Beta, Gamma and Delta — that is well established for these two vaccines," Bhargava said.