Moderna details positive Phase 1 experimental COVID-19 vaccine results

American biotech company Moderna has announced positive interim clinical data related to its mRNA-1273 vaccine candidate targeting the novel coronavirus. The positive results come from the NIH's National Institute of Allergy and Infectious Diseases (NIAID) Phase 1 clinical trial. The test involved a total of eight volunteers who received two doses of the experimental vaccine, which will be heading into larger tests going forward.

Moderna's experimental mRNA-1273 vaccine was given to participants ages 18 to 55 in two doses: 25µg and 100µg. A third dose of 250µg was also given a single time. All three dose levels produced increases in immunogenicity, according to Moderna, with the increases having been dependent on dose.

The company says that the experimental vaccine was 'generally safe and well-tolerated' with the only grade 3 issue having been redness at the injection site that appeared at 100µg in one participant. The worse 'adverse events' noted during the trial happened after the second dose in three participants at a dose level of 250µg.

All of the adverse events were described as 'transient and self-resolving.' Moderna says there weren't any experiences of grade 4 or serious issues. With these favorable results in place, Moderna anticipates that it will lead a Phase 2 study of the vaccine at the higher dose levels of 50µg and 100µg and expects that the Phase 3 study will start in July with doses between 25µg and 100µg.

Moderna Chief Medical Officer Tal Zaks, MD, Ph.D., said:

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. 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.