A NEW research by ICMR-NIV and Bharat Biotech indicates that a Covaxin booster dose is effective against both the Delta and Omicron forms of Covid-19.
“The booster dose of Covaxin improved neutralising antibody response against VoCs, particularly Delta and Omicron. This is a promising study, said ICMR’s Samiran Panda.
The study’s findings will be confirmed in human studies. According to Dr. Panda’s procedure, the study was conducted earlier but is yet to be published.
The ICMR-NIV study is titled “Protective effectiveness of Covaxin against Delta and Omicron variants in the hamster model” and was posted on bioRxiv on June 14.
NIV and Bharat Biotech researchers studied the protective efficacy of Covaxin after second and third doses against the Delta variant in a Syrian hamster model (animal model to study human-associated diseases).
After a virus challenge, researchers investigated clinical findings, viral load reduction, antibody response, and respiratory disease severity. Both the second and third doses of the Covaxin immunised group saw a decrease in lung viral load and lung lesions following the Delta variant challenge, the paper added.
In the Delta infection trial, researchers evaluated the defensive response between both the second and third dose regimens and observed the booster dosage vaccination’s benefits. Despite comparable antibody levels, the third vaccine lowered respiratory disease symptoms.
In the second trial, test subjects reported less virus shedding, lung viral load, and lung illness severity after three doses of vaccination against Omicron variants BA.1 and BA.2.
Natural infection or vaccination-generated immunity tends to diminish over time, and newly developing variations challenge acquired immunity with immune escape capabilities, according to the study authors. Researchers claim this requires ongoing monitoring of virus genetic alterations and variant features. Booster doses have been approved by regulatory authorities in various countries to boost the efficacy of many Covid-19 vaccines.