The emergence of the Delta and Delta Plus variants has once again put India in a state of high alert.
Two weeks after the Indian government declared the COVID-19 variant Delta Plus one of concern, health experts say the mutation, also known as AY.1 or B.1.617.2.1, has an extra mutation in the spike protein of the SARS-CoV-2 virus and poses a new challenge for the country, even with nationwide mass vaccination underway.
EXPERTS IN INDIA RAISE CONCERN
The first case of Delta Plus was found in India on June 11.
Initially, the Delta Plus variant was declared by India's health ministry as a variant of interest; however, later on, it was classified as a variant of concern for its characteristics of increased transmissibility, stronger binding to the receptors of lung cells and potential reduction in monoclonal antibody response.
While the Delta variant had largely been blamed for the second wave of the COVID-19 pandemic in India, the new, more virulent "plus version" variant is being feared ahead of a potential third wave.
Studies have found it can replicate faster, spread more easily, and bind more strongly to lung cell receptors, according to Sunit K Singh, professor of molecular immunology at the Institute of Medical Sciences, Banaras Hindu University.
"Also, in a pre-print study yet to be peer-reviewed, Delhi researchers found the variant caused three-quarters of 'breakthrough infections' in the city. These are infections in people who've been vaccinated," Singh wrote in an article, noting that 76 percent of these "breakthrough infections" carried the Delta variant.
Shahid Jameel, India's top virologist and a former member of the Indian SARS-CoV-2 Genomic Consortia, also expressed concerns regarding the Delta Plus variant, saying that the new mutant may be capable of dodging immunities, both from COVID-19 vaccine as well as from earlier infections.
"If this was any mutation at random, we would not be worried so much," Jameel said. "Since this mutation has come up in something that was already a variant of concern, it is logical to call it a variant of concern."
Jameel added at present there was no data available to comment on how severe the Delta Plus variant could be.
"Given the limited number of cases so far in the country (of Delta Plus), as of now the new variant does not seem to be a major cause for worry," said Anant Bhan, a New Delhi-based public health expert.
Bhan suggested tracking its spread while maintaining public health precautions and enhancing vaccination coverage.
WHO ALARM ON DELTA VARIANT
The World Health Organization last week said the Delta variant is present in nearly 100 countries and warned that in the coming months the highly transmissible strain will become the dominant variant of COVID-19 globally.
"Ninety-six countries have reported cases of the Delta variant, though this is likely an underestimate as sequencing capacities needed to identify variants are limited," the WHO said in its recent COVID-19 Weekly Epidemiological Update. "Given the increase in transmissibility, the Delta variant is expected to rapidly outcompete other variants and become the dominant variant over the coming months."
WHO Director-General Tedros Adhanom Ghebreyesus said the Delta variant is "the most transmissible of the variants identified so far" and is spreading rapidly among unvaccinated populations.
"I know that globally there is currently a lot of concern about the Delta variant, and WHO is concerned about it too," he said.
Tedros also said that scenes of overflowing hospitals are again becoming the norm in countries with low vaccination coverage, adding that no country is "out of the woods yet."
EXTENDING VACCINE COVERAGE
Experts say the Delta Plus variant is an extra mutation of the Delta variant and illustrates its characteristics. Apart from following COVID-19 protocol and related behaviour, they emphasize the importance of mass vaccination.
"We must continue to get maximum numbers of people vaccinated, increase genomic surveillance to track the evolution of the virus and follow COVID-19 appropriate behavior," Singh said.
The unique mutations in the Delta variant mean the virus can escape the immune system to some extent. Indeed, Delta has shown to reduce the efficacy of vaccines somewhat, he said.
"This means a single dose of vaccine may offer reduced protection. However, a second dose has been shown to produce enough antibodies against symptomatic infection and severe disease. It's important to remember most COVID-19 vaccines don't provide absolute sterilising immunity, but work to reduce the severity of the disease," he said.
The vaccination program against COVID-19 in India started on Jan. 15, and the Indian government aims to vaccinate the entire population by the end of this year. The federal health ministry said on Thursday that over 364 million doses have been administered.