Ocugen and its partner Bharat Biotech have announced that Sera from people vaccinated with a booster dose of Covid-19 vaccine candidate Covaxin (BBV152) showed to neutralise the Omicron and Delta variants of the SARS-CoV-2 virus in a study.

Bharat Biotech developed the well purified and inactivated vaccine in partnership with the Indian Council of Medical Research (ICMR) – National Institute of Virology (NIV).

In the study carried out at Emory University in the US, the booster was given to individuals six months following the initial two-dose vaccine regimen of Covaxin.

Ocugen entered a contract with the Emory Vaccine Center in Atlanta to analyse the vaccine against the Omicron variant using human immune sera collected from subjects who are part of the Phase II clinical trial underway.

Sera was collected 28 days following the booster administration and tested in a neutralisation assay.

The FRNT50 geometric mean titers (GMTs) of neutralising antibodies against Omicron in the samples after three doses of the vaccine were found to be 75 versus 480 and 706 against the Delta and vaccine strain, D614G, respectively.

Covaxin-boosted sera was also found to possess similar neutralisation activity as the mRNA vaccine-boosted sera against Omicron.

More than 90% of all people who received the booster vaccine had neutralising antibodies against Omicron while all tested serum samples demonstrated to neutralise the Delta variant.

In prior studies, Covaxin was found to have neutralising potential against Alpha, Beta, Delta, Zeta and Kappa variants.

Bharat Biotech chairman and managing director Dr Krishna Ella said: “The positive neutralisation responses against the Omicron and Delta variants validate our hypothesis of a multi-epitope vaccine generating both humoral and cell-mediated immune responses.

“Our goals of developing a global vaccine against Covid-19 have been achieved with the use of Covaxin as a universal vaccine for adults and children.”

Last November, Ocugen sought the US Food and Drug Administration (FDA) emergency use authorisation (EUA) for the vaccine candidate to be used in children in the age group of two to 18 years.

Furthermore, an Investigational New Drug application is being discussed with the FDA to facilitate an immuno-bridging study among US subjects.