Moderna vaccine mRNA-1273 shows early promise in human trial

"The levels of neutralising antibodies on day 43 were at or above levels generally seen in convalescent sera," explained the drug maker.

"mRNA-1273 was generally safe and well tolerated, with a safety profile consistent with that seen in prior Moderna infectious disease vaccine clinical studies," said the company.

Based on the interim Phase 1 data, the Moderna-led Phase 2 study will soon start, with the aim of selecting a dose for pivotal studies.

Moderna stock surged 26 per cent in trading before the market opened in the US. European markets were also up.

Moderna anticipates the dose for the Phase 3 study to be between 25 µg and 100 µg and expects Phase 3 trial initiation in July, subject to finalisation of the clinical trial protocol.

"These interim Phase 1 data, while early, demonstrate that vaccination with mRNA-1273 elicits an immune response of the magnitude caused by natural infection starting with a dose as low as 25 µg," said Tal Zaks, Chief Medical Officer at Moderna.

"When combined with the success in preventing viral replication in the lungs of a pre-clinical challenge model at a dose that elicited similar levels of neutralizing antibodies, these data substantiate our belief that mRNA-1273 has the potential to prevent COVID-19 disease and advance our ability to select a dose for pivotal trials," Zaks added.