Moderna has dosed the first subject in the Phase I Eclipse clinical trial of its Epstein-Barr Virus (EBV) vaccine candidate, mRNA-1189.

The EBV vaccine comprises four messenger ribonucleic acids (mRNAs) that encode EBV envelope glycoproteins, namely gH; gL; gp42 and gp220.

These glycoproteins are required for the entry of the virus into B-cells, as well as epithelial surface cells.

The observer-blind, randomised, placebo-controlled trial will evaluate the safety and tolerability of the vaccine in healthy adult subjects aged 18 to 30 years.

The trial will enrol around 270 subjects and be carried out at nearly 15 centres in the US.

Moderna CEO Stéphane Bancel said: “EBV is one of the most common viral infections in the world, and despite the fact that it causes infectious mononucleosis, which impacts millions of adolescents globally, no vaccine is currently available.

“The start of this Phase I study is a significant milestone as we continue to advance mRNA vaccines against latent viruses, which remain in the body for life after infection and can lead to chronic medical conditions.”

A prevalent viral infection, EBV is contracted in early stages of childhood or adolescence through bodily fluids such as saliva.

Primary EBV infection in adolescence can cause infectious mononucleosis (IM), a clinical syndrome that includes fever, sore throat, fatigue and lymphadenopathy.

Candidates against respiratory, latent and tropical viruses are part of the mRNA vaccine portfolio of Moderna.

The company focuses on the development of shots against latent viruses, including EBV, cytomegalovirus (CMV) and human immunodeficiency virus (HIV), which currently have no approved vaccines.

Last August, Moderna dosed the first participant in the Phase I trial of mRNA-6231 to treat autoimmune diseases.