Novavax's updated Covid shot shows immune response against subvariant Eris

Novavax Inc said on Tuesday its updated protein-based Covid-19 vaccine generated an immune response against emerging forms of coronavirus such as the "Eris" subvariant in small studies in animals.

Covid infections and hospitalizations have been rising in the United States, Europe and Asia, with more cases in recent months attributed to the EG.5 subvariant — nicknamed "Eris" — a descendant of the Omicron lineage that originally emerged in November 2021.

For the fall season, Covid vaccine makers are gearing up with updated shots that target the Omicron subvariant XBB.1.5. Both Moderna and Pfizer have said their shots show promise against Eris too.

Pending approval from health regulators in the United States and Europe, the companies expect the updated shots to be available in the coming weeks for the autumn vaccination season.

Pfizer and German partner BioNTech SE said their updated vaccine generated an immune response against Eris, while Moderna said preliminary trial data shows its own shot produced antibodies against Eris and another related subvariant dubbed "Fornax".

Shares of Novavax rose 3.2% to $8.33 in volatile premarket trading after the company said its updated shot generated virus-neutralizing antibodies for XBB subvariants including EG.5.1 and XBB.1.16.6 in the pre-clinical studies.

EG.5 accounted for about more than 17 per cent of Covid-19 cases in the United States, according to the latest government data.

The World Health Organization has classified Eris as a "variant of interest", indicating that it should be more closely watched than others because of mutations that might make it more contagious or severe.