Elevated neutralization of Omicron with sera of COVID-19 recovered and breakthrough cases vaccinated with Covaxin than two dose naïve vaccinees

The study assessed the neutralization ability of sera from individuals vaccinated with Covaxin against the Omicron variant, comparing COVID-19 naïve, recovered, and breakthrough cases. It found that breakthrough cases exhibited the highest neutralizing activity, followed by recovered cases, while naïve cases showed significantly lower neutralization, indicating waning immunity three months post-vaccination. Omicron demonstrated pronounced resistance to neutralization compared to B.1, Beta, and Delta variants. Despite reduced neutralization, the immune response was sufficient to protect against severe disease. The study highlighted the importance of booster doses for enhanced protection, supported by findings of increased neutralizing antibody responses with booster doses of Covaxin.