ICMR Study: Delta Variant Behind Most Breakthrough COVID Infections

A total of 677 clinical samples were collected, out of which three fatalities were reported.

A recent study conducted by the Indian Council of Medical Research (ICMR) has revealed that the Delta variant of SARS-COV-2 (Coronavirus) has been responsible for a vast majority of clinical cases of breakthrough infection.

As per PTI, 86.09 percent of the breakthrough infections studied by ICMR were caused by the Delta variant (B.1.617.2) in different regions of India except for the northern region where the Alpha variant predominated.

A total of 677 clinical samples of individuals who had received two doses and one dose of vaccines and had tested positive for COVID-19 were collected from 17 states for this study.

KEY HIGHLIGHTS OF THE ICMR STUDY

The study further reveals:

• 67 cases (9.8 percent) required hospitalisation

• Three (0.4 percent) fatalities were reported

• 71 percent cases were symptomatic with one or more symptoms

• 29 percent cases were asymptomatic

• 604 patients had received Covishield vaccine

• 71 patients had received Covaxin

• Two patitents had received Sinopharm vaccine

• 85 of the 677 patients analysed acquired COVID-19 infection after taking the first dose of the vaccine

• 592 of the 677 patients analysed acquired COVID, after receiving both doses of the vaccine

• Break through infections predominantly occurred through Delta variants, indicating its high community transmission during the period between March and June, followed by Alpha and Kappa variants

• Southern, western, eastern and north-western regions of India predominantly reported breakthrough infections from mainly Delta, followed by Kappa

Further, the ICMR study was quoted by PTI as saying that two new COVID variants Delta AY.1 and AY.2 were also identified in the study samples.

“Delta AY.1 and AY.2 is characterized by the presence of K417N mutation in the spike protein region. K417N, E484K, L452R, and E484Q are the mutations known to disrupt receptor binding domain (RBD) binding capacity and make them more infectious by immune escape mechanisms against the current vaccines.”

ICMR Study

“This indicates improved virus fitness to evade immune responses and survive against the vaccines,” the study further added.

WHERE WERE THE SAMPLES COLLECTED FROM?

The samples were coerced from 17 states and union territories:

• Maharashtra

• Kerala

• Gujarat

• Uttarakhand

• Karnataka

• Manipur

• Assam

• Jammu and Kashmir (J&K)

• Chandigarh

• Rajasthan

• Madhya Pradesh

• Punjab

• Puducherry

• New Delhi

• West Bengal

• Tamil Nadu

• Jharkhand

(With inputs from PTI)