New York, Mar 16 (IANS): Biotechnology company Moderna has announced that first participants have been vaccinated in the Phase 1 study of mRNA-1283 -- a potential refrigerator-stable Covid-19 vaccine that could facilitate easier distribution and administration, especially in developing countries.

Moderna said the new Covid-19 vaccine candidate could be stored and shipped in refrigerators instead of freezers.

"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 potential for developing countries," said Stephane Bancel, CEO of Moderna.

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).

This Phase 1 study will evaluate three dose levels, 10 microgrammes, 30 microgrammes, and 100 microgrammes, of the mRNA-1283 vaccine candidate given to healthy adults as a 2-dose series, 28 days apart, and one dose level, 100 microgrammes, of mRNA-1283 given to healthy adults in a single dose, the company said.

These will be compared with a 2-dose series of 100 microgrammes of mRNA-1273, the currently authorised dose level.

mRNA-1283 is intended to be evaluated in future studies for use as a booster dose for previously vaccinated or seropositive as well as in a primary series for seronegative individuals.

The Moderna Covid-19 vaccine is an mRNA vaccine against Covid-19 encoding for a prefusion stabilised form of the Spike (S) protein, which was co-developed by Moderna and investigators from the National Institute of Allergy and Infectious Disease's (NIAID) Vaccine Research Center.

On December 18, 2020, the US FDA authorised the emergency use of the Moderna Covid-19 vaccine in individuals 18 years of age or older.

The company has also received authorisation for its Covid-19 vaccine from health agencies in Canada, Israel, the European Union, the UK, Switzerland, Singapore and Qatar.

Additional authorisations are currently under review in other countries and by the World Health Organisation (WHO), the company said.