Artwork by Sophia Zhao.
The results of the Moderna SARS-CoV-2 vaccine phase 1 clinical trial published last week have sparked new optimism in the race for a COVID-19 vaccine. Individuals that received the mRNA-1273 coronavirus vaccine and booster shot produced antibodies at levels similar to those observed in recovered COVID-19 patients. Three different dosages of the vaccine (25 μg, 100 μg, and 250 μg) were administered 28 days apart to 45 healthy adults between the ages of 18 and 55. Participants reported moderate-to-severe side effects, none of which required hospitalization.1
The Moderna vaccine employs mRNA-1273 that encodes the stabilized perfusion SARS-CoV-2 spike protein. This method has been successfully used to elicit immune responses against other coronaviruses, including SARS-CoV and MERS-CoV2. Other manufacturers, including Pfizer and BioTech, are also conducting clinical trials on mRNA vaccines that employ similar technology. Moderna is set to start a three hundred thousand-person clinic trial later this month.
The production of an effective vaccine within months is almost too good to be true; it remains to be seen whether this vaccine produces a long-lasting immune response. It is also unclear what levels of antibody titers are necessary to confer immunity from the virus. In any case, these results give us reason for optimism.