JOIN USDelta variant behind 86% of breakthrough Covid-19 infections: ICMR study
An Indian Council of Medical Research (ICMR) study has found that among 677 Covid positive samples of those who were vaccinated, 86.09 per cent were infected by the Delta variant (B.1.617.2).
As many as 181 samples (26.7 per cent) were taken from Karnataka’s National Institute of Virology in Bengaluru and Mysore Medical College, which is the largest share in the sample pool. The rest of the samples were taken from 16 other states and union territories. While 9.8 per cent (67) cases required hospitalisation, the fatality was observed in only 0.4 per cent (3) cases. “This clearly suggests that the vaccination does provide a reduction in hospital admission and mortality,” the ICMR said in its study.
A breakthrough infection is one where an individual gets infected even though he/she is vaccinated. This study is the largest and first nationwide study of breakthrough infections in India.
A source said, “The ICMR findings confirm what the Karnataka health department also independently found. Out of 11,400 breakthrough infections that it analysed in the state, 9,000 of whom received one dose and 2,000 of whom received both doses, 90 died and only 87 were hospitalised.”
The clinical samples for the ICMR analysis were collected in April and May during the peak of the second wave in the state. Out of 677 patients, 85 got infected after the first dose and 592 were infected after getting both doses. While 604 (89.2 per cent) of these had received the Covishield vaccine, 71 (10.5 per cent) had received Covaxin and two (0.3 per cent) were vaccinated with Sinopharm.
A total of 482 cases (71 per cent) were symptomatic with one or more symptoms, while 29 per cent had asymptomatic SARS-CoV-2 infection.
Dr Vishal Rao, member of the State Genomic Surveillance Committee said the ICMR study proves that a majority of the Karnataka samples had Delta, Kappa and Alpha variants, which is corroborated by state’s numbers. “The predominant strain in the second wave was Delta variant. Among the vaccinated, the fatality rate is less than 1 per cent,” he said.
“Even a single dose of vaccine confers protection against morbidity and mortality. This tells us that 100% of our state’s population should be given at least one dose as soon as possible. Even the intensity of the infection was drastically reduced whether they were asymptomatic, hospitalised or home-quarantined,” he stressed.
Also, only 134 of the 677 Covid patients had comorbidities, and 458 had no comorbidities.