This week, Moderna began dosing participants in two important studies. On Monday, the first adult participants were dosed in the Phase 1 study of mRNA-1283, the company’s next-gen COVID-19 vaccine that could be used as a booster shot in the future. On Tuesday, the biotech company dosed child participants in the Phase2/3 study of its currently approved mRNA-1273 COVID-19 vaccine.
Currently, there are no approved COVID-19 vaccines for children under the age of 16. Pfizer and BioNTech’s vaccine is approved for emergency use authorization in those aged 16 and older, while Moderna’s mRNA-1273 is approved adults aged 18 and older.
Moderna’s current trial, called KidCOVE, is evaluating the use of the vaccine candidate in children 6 months to less than 12 years old. The company intends to enroll approximately 6,750 pediatric patients through the U.S. and Canada for the two-part trial.
In Part 1, each participant 2 to less than 12 years old may receive one of two dose levels—50 or 100 μg. Additionally, each participant 6 months to less than 2 years old may receive one of three dose levels—25, 50 and 100 μg.
Then, an interim analysis will be conducted to determine which dose will be used in Part 2, the placebo-controlled expansion portion of the study. Participants will be followed through 12 months after the second vaccination. Vaccine effectiveness will either be inferred through achieving a correlate of protection, if established, or through immunobridging to the young adult (ages 18-25) population. Safety will also be a primary endpoint of the study.
Meanwhile, Moderna is evaluating the mRNA-1283, a next-generation vaccine candidate against COVID-19, in a Phase 1 study. This vaccine encodes for portions of the SARS-CoV-2 spike protein critical for neutralization.
This Phase 1 study will evaluate three dose levels—10, 30 and 100 µg—given to healthy adults as a two-dose series 28 days apart, as well as a 100 µg dose given to adults in a single shot. The results will be compared with a two-dose series of 100 µg of mRNA-1273, the currently approved vaccine and dose level.
The encoded mRNA-1283 antigen is being developed as a potentially refrigerator-stable mRNA vaccine that will facilitate distribution and administration by healthcare providers. In the future, the mRNA-1283 vaccine candidate will be evaluated for use as a booster dose for previously vaccinated or seropositive individuals, as well as in a primary series for seronegative individuals.