This could mean that Covid-19 vaccines are eight times less effective against the Delta variant compared to the original strain of SARS-CoV-2 first detected in China’s Wuhan.
According to media reports, the study was conducted on more than 100 healthcare workers at three centres in India, including Delhi’s Sir Ganga Ram Hospital. The joint research, SARS-CoV-2 B.1.617.2 Delta Variant Emergence and Vaccine Breakthrough: Collective Study, was conducted by scientists from India and their counterparts from the Cambridge Institute of Therapeutic Immunology and Infectious Disease.
“Across all scenarios considered, our results suggest the Delta variant is both more transmissible and better able to evade prior immunity elicited by the previous infection as compared to previously circulating lineages,” it said.
Researchers found that Delta was the dominant strain among fully vaccinated healthcare workers infected with Covid-19. The respiratory viral loads were also higher in the cases of these healthcare workers compared to those diagnosed with non-Delta variants.
However, the paper also assured large-scale vaccination will likely protect against moderate to severe disease, and also reduce hospitalisations due to the Delta variant.
