The Delta variant grew to become the dominant variant in India due to its improved ability to jump to new hosts, a new study suggested. The finding shows the unique set of mutations makes the virus more infective, leads to a higher viral load in people, and causes larger outbreak clusters.
The findings by researchers in India have taken into account the outbreak patterns among healthcare workers in three Indian cities, lab analysis of how the variant reacts to antibodies and the way in which the virus infects human cells, particularly lungs.
As per Hindustan Times, the study has made several crucial findings, some of which have also been reflected in real-world data coming from the UK. The study was conducted by the researchers from the Institute of Genomics and Integrative Biology (IGIB) in collaboration with Cambridge University’s Gupta Lab.
“The main finding of the paper is that the Delta variant has a good immune escape potential as shown in the lab. It also quickly replaced other variants and caused most of the breakthrough infections (infection after complete vaccination) in healthcare workers. For the people, what this means is that we have to be very cautious and behave appropriately, especially now that we are also seeing cases of Delta Plus. We still do not know anything about its immune escape potential. The studies have just started,” said Dr Rajesh Pandey, one of the authors of the paper and senior scientist at the Institute of Genomics and Integrative Biology.
“Delta variant has the maximum transmissibility yet seen, and reduces neutralisation protection from previous infections and vaccines,” said Dr Anurag Agarwal, one of the authors of the study and the director of the Institute of Genomics and Integrative Biology.
Reportedly, based on Covid-19 cases and deaths reported from Mumbai showed that by the end of January there was a 2 per cent increase in the transmissibility of the Delta variant against all others in circulation. And a 32 per cent increase in immune evasion from a previous infection (if the researchers assumed that there was 30% under-reporting of deaths). The proportions go up if the assumption is 50% and 70% under-reporting of Covid-19 deaths.
Reportedly, the scientists also found that the Delta variant had a replication advantage over Alpha variant in the lab and as per samples of over 100 healthcare workers from three Delhi hospitals who got breakthrough infections were sequenced, most of them were caused by the Delta variant.