People recovered from COVID-19 and vaccinated have higher protection against Delta variant: Study
Jul 05, 2021
New Delhi [India], July 5 : Breakthrough cases and the COVID-19 recovered individuals with one or two doses of vaccine had relatively higher protection against Delta variant in comparison to those who were administered either one or two doses of Covishield, according to a study.
According to an ICMR study on "Neutralisation of Delta variant with sera of Covishield vaccines and COVID-19 recovered vaccinated individuals", prior vaccination results in less severe disease against subsequent infection provide evidence that both humoral and cellular immune response play an important role in protection.
"There is limited information available on the duration of protective immune response post-infection, vaccination or breakthrough infection with SARS-CoV-2. In this study, we have evaluated immune response in sera of the Covishield vaccinated individuals belonging to category: I. one dose vaccinated, II. two doses vaccinated, III. COVID-19 recovered plus one dose vaccinated, IV. COVID-19 recovered plus two doses vaccinated and V. breakthrough COVID-19 cases," the study said.
"The findings of the study demonstrated that the breakthrough cases and the COVID-19 recovered individuals with one or two dose of vaccine had relatively higher protection against Delta variant in comparison to the participants who were administered either one or two doses of Covishield," it said.
The study said the high transmissibility associated with the Delta variant has led to the second wave of pandemic in India which affected millions of people.
"The recent emergence of B.1.617 lineage has created grave public health problem in India. The lineage further mutated to generate sub-lineages B.1.617.1 (Kappa), B.1.617.2 (Delta), B.1.617.3. Apparently, the Delta variant has slowly dominated the other variants including B.1.617.1 (Kappa), B.1.617.2 (Delta), B.1.617.3," it said.
"With this, World Health Organization has described this sub-lineage as variant of concern. The high transmissibility associated with Delta variant has led to second wave of pandemic in India which affected millions of people. Besides this, variant of concerns has been reported to show lower neutralization to several approved vaccines. This has led to breakthrough infections after completion of vaccination regimen," it said.
