Development was confirmed by a study taken by ICMR
A single dose of Covaxin (BBV152) given to people already infected with Covid-19 results in the same or increased antibody response as uninfected people given two doses of Covaxin, according to a study by the Indian Council of Medical Research (ICMR).
The Government’s premier health research body undertook a pilot study to examine SARS-CoV-2 specific antibody responses after day 0 (baseline before vaccination), after the first dose (month 1) and then post-second dose (month 2) of BBV152 in a group of healthcare professionals as well as frontline workers.
The antibody responses of individuals with confirmed pre-vaccination SARS-CoV-2 infection were compared with those individuals without prior evidence of infection.
The blood specimens were collected from healthcare professionals and frontline workers who received BBV152 vaccine at vaccination centres in Chennai, India, from February to May 2021. Blood samples were collected before receiving the first dose of BBV152. Prior infection with SARS-CoV-2 was determined by SARS-CoV-2 IgG positivity at baseline. The study was approved by the Ethics Committee of ICMR-NIRT.
Antibody levels were measured at three-time points: on the day of vaccination (baseline), at month one following the first dose and at month two following the second dose.
The results were determined via a calibration curve, which are an instrument specifically generated by a two-point calibration and a master curve provided via the reagent QR code.
Almost all participants with prior Covid-19 infection except two had detectable antibodies at the time of vaccination. This study offers evidence in support of public health-oriented and immunologically sustained vaccine strategies.
Lokesh Sharma, scientist and Media Coordinator, ICMR, said, “This is a pilot study. If such findings are confirmed in large population studies, a single dose of BBV152 vaccine may be recommended to previously confirmed Covid patients so that individuals could attain the larger benefit of a limited vaccine supply.”