COVID-19 vaccine
COVID-19 vaccine Reuters

Moderna on Wednesday said its new COVID booster candidate, which it is hoping to get approved this fall, performed well against Omicron's latest subvariants, AFP reported.

The US biotech company announced earlier this month that the so-called "bivalent" vaccine, which targets the original COVID strain and original Omicron BA.1, performed better against both compared to its original COVID vaccine called Spikevax.

In new results from a clinical study published Wednesday, the company said that the booster also did well against BA.4 and BA.5, Omicron's latest subvariants that are becoming dominant thanks to their increased ability to evade prior immunity, and enhanced transmissibility.

The bivalent booster elicited high levels of infection-blocking antibodies against BA.4 and BA.5 both in people who were previously infected and those not previously infected.

However even those high levels were still one third the levels achieved against the original Omicron strain, BA.1, the company said.

"We will submit these data to regulators urgently and are preparing to supply our next generation bivalent booster starting in August, ahead of a potential rise in SARS-CoV-2 infections due to Omicron subvariants in the early fall," said Moderna CEO Stephane Bancel in a statement quoted by AFP.

Pfizer and BioNTech have also begun enrollment for a clinical trial to test the safety and immune response of their Omicron-specific COVID-19 vaccine in adults aged up to 55.