• A published and peer-reviewed study reveald the anti-COVID-19 vaccine mRNA-1273 generated an immune response in all the volunteers involved in a Phase 1 study
  • The study said there were "no trial-limiting safety concerns were identified"
  • Moderna will begin its Phase 3 study of mRNA-1273 this month

Massachusetts-based biotech firm Moderna Inc. on Tuesday announced mRNA-1273, its candidate vaccine against COVID-19, had produced a “robust” immune response in all 45 patients involved in its Phase 1 human trials. In March, mRNA-1273 became the first candidate vaccine to enter a phase 1 human trial.

Moderna is the smallest of the five firms being financially supported by the federal government under Operation Warp Speed, a project that aims to quickly develop a COVID-19 vaccine in record time.

The Phase 1 results were revealed in a study published Tuesday in the prestigious peer-reviewed journal, the New England Journal of Medicine (NEJM). The study carries the title, "An mRNA Vaccine against SARS-CoV-2 -- Preliminary Report" and was written by the mRNA-1273 Study Group.

The Phase 1 study was a dose-escalation, open-label trial involving 45 healthy adults, 18 to 55 years of age. These volunteers received two vaccinations, 28 days apart, with mRNA-1273 in a dose of 25 μg, 100 μg, or 250 μg.

After the first vaccination, researchers saw antibody responses were higher with a higher dose. Serum-neutralizing activity was detected after the second vaccination. All 45 patients produced neutralizing antibodies, which is a type of protein needed to build immunity.

The vaccine elicited a “robust” immune after two vaccinations in all participants in all dose cohorts, according to Moderna. The company revealed the levels of neutralizing antibodies in volunteers in the high-dose group were four times higher than in recovered COVID-19 patients.

On the other hand, the study also reported side-effects associated with the dosing in among half the volunteers. These complications included fatigue, chills, headache, myalgia and pain at the injection site.

Overall, the study concluded the mRNA-1273 vaccine "induced anti–SARS-CoV-2 immune responses in all participants, and no trial-limiting safety concerns were identified." The study said these findings support further development of this vaccine.

“These Phase 1 data demonstrate that vaccination with mRNA-1273 elicits a robust immune response across all dose levels and clearly support the choice of 100 µg in a prime and boost regimen as the optimal dose for the Phase 3 study,” said Dr. Tal Zaks, Moderna’s chief medical officer.

“We look forward to beginning our Phase 3 study of mRNA-1273 this month to demonstrate our vaccine’s ability to significantly reduce the risk of COVID-19 disease.”

During the Phase 3 study, researchers intend to enroll 30,000 adult participants. One group will be injected with 100 µg of the vaccine on day 1 and again on day 29. A second group will be injected with two doses of a placebo for comparison.

Moderna, whose headquarters are seen here in Cambridge, Massachusetts, is 'temporarily ahead' in the vaccine race, Fauci said
Moderna, whose headquarters are seen here in Cambridge, Massachusetts, is 'temporarily ahead' in the vaccine race, Fauci said AFP / Joseph Prezioso