American pharmaceutical and biotechnology company Moderna has started an early-stage study of a new Covid-19 vaccine candidate.

The company has dosed the first patients in the Phase I study of mRNA-1283, which is being developed as a potential refrigerator stable mRNA vaccine to enable easier distribution.

The study will evaluate the safety and immunogenicity of mRNA-1283 at three dose levels.

The vaccine candidate will be administered at 10µg, 30µg, and 100µg doses on healthy adults as a two-dose series with a gap of 28 days, as well as one dose at 100µg.

The results will be compared with the currently authorised two-dose series of 100µg of mRNA-1273.

Moderna CEO Stéphane Bancel said: “We are pleased to begin this Phase I study of our next generation Covid-19 vaccine candidate, mRNA-1283.

“Our investments in our mRNA platform have enabled us to develop this next generation vaccine candidate, which is a potential refrigerator-stable vaccine that could facilitate easier distribution and administration in a wider range of settings, including potentially for developing countries.”

mRNA-1283 encodes for the portions of the SARS-CoV-2 spike protein critical for neutralisation, specifically the Receptor Binding Domain (RBD) and N-terminal Domain (NTD).

In future, the company plans to test the efficacy of mRNA-1283 for use as a booster dose for previously vaccinated as well as seropositive individuals.

Last week, Moderna began dosing the first subjects in a study assessing its Covid-19 booster vaccine candidates. Subjects are being enrolled by amending the ongoing Phase II clinical study.