Biological E develops next gen XBB1.5 variant Covid vax, awaits clearance

XBB 1.5 is a sub-variant of Omicron, and a sub-linear of XBB variant. It is a recombinant of the two BA.2 sublineages, and carries a mutation of the spike protein (F486P)

Biological E (BE) is awaiting the drug regulator’s clearance to begin clinical trials of its vaccine to fight the XBB1.5 variant of the Sars-CoV-2 virus, according to a senior official of the Hyderabad-based manufacturer.

The move comes at a time when Omicron and its sub-variants have remained the dominant strains in circulation for close to two years now. Most of the vaccines available and administered in India are based on the original Wuhan strain of the virus. As of now, Gennova Biopharmaceuticals has launched a vaccine, Gemcovac-OM, which is based on the Omicron variant.

Vikram Paradkar, executive vice-president, vaccine division, Biological E, told Business Standard that the company had developed a “next-generation” Covid-19 vaccine based on the XBB1.5 variant of the Sars-CoV-2 virus according to World Health Organization recommendations.

Paradkar said, “BE’s candidate vaccine has finished all required pre-clinical animal studies, which suggest that it will provide adequate protection against the currently circulating variants.”

The Covid-19 Subject Expert Committee of the Central Drugs Standard Control Organisation (CDSCO) has approved BE’s clinical trial application, he said, adding that the company was awaiting a final from the regulator to begin the clinical trials of the XBB variant vaccine in India.

Paradkar added that BE also had the manufacturing infrastructure for producing variant vaccines to initiate supply at a short notice.

XBB1.5 is a sub-variant of Omicron, and a sub-linear of the XBB variant. It is a recombinant of the two BA.2 sub-lineages, and carries a mutation of the spike protein (F486P) that increases infectivity due to increased binding affinity to the ACE2 receptor.

Recently, Pune-based Serum Institute of India, the world’s largest vaccine maker by volume, said that they were also working on a XBB1.5 variant vaccine that would be effective against the current variant of interest, JN.1.

The JN.1 sub-variant is a descendant of BA.2.86 (also known as Pirola), which itself is a sub-variant of the widely circulating Omicron.

Paradkar said that BE also had a significant stockpile of Corbevax, their protein-sub-unit vaccine that was administered in children earlier apart from being approved as a mix-and-match booster shot after two doses of Covaxin and Covishield.

The company has a stockpile of various components necessary to manufacture the variant vaccine (protein antigen and adjuvants) that can be formulated at large scale quickly for supply of large quantities.

An article published in the Gavi, the vaccine alliance website written by science journalist Linda Geddes, said: “Human studies have also assessed the immune response induced by the BA.4/5 vaccine against XBB.1 (which XBB.1.5 descended from) and several descendants of the BA.2 and BA.4-BA.5 sub-variants. One of these studies, published in The New England Journal of Medicine, suggested that older individuals who received a fourth dose (second booster) of the BA.4/5 vaccine experienced a greater increase in antibodies against XBB.1 and descendants of the BA.2 and BA.4-BA.5 sub-variants that were circulating in mid-late 2022, compared to people who received a fourth dose of the original vaccine.”