Moderna Vaccine: Early Results Provide Hope

By Annette Pinder


Here’s some good news: Moderna’s COVID-19 vaccine mRNA-1273, described in our last issue, has completed the first phase of study. The vaccine, which was given to 45 people, resulted in all participants developing an immune response to the virus. While some reported side effects such as fatigue, chills, headache, and muscle pains, none were serious.

Scientists, encouraged by the results, began phase II of the study, at which time the Moderna vaccine was tested in a larger group of people. During phase III, the vaccine will be tested on a much larger group of people and, if all goes well, the final step will be seeking FDA approval of the vaccine.

The Moderna study is led by the National Institute of Allergy and Infectious Diseases of the National Institutes of Health and results of the first phase were published in The New England Journal of Medicine. During that phase, participants were divided into three groups of 15 people each. All received two vaccinations 28 days apart, with each group receiving a different strength of the vaccine — either 25, 100, or 250 micrograms. All participants tested developed antibodies that can block the infection.

The phase II study results are not yet published, but involved 300 heathy adults ages 18-55, and another 300 ages 55 and older. During phase III, Moderna hopes to include about 30,000 participants in the U.S. at the 100-microgram dose level. If successful, it will provide the final evidence that Moderna requires to move the vaccine to market. Moderna says it is on track to produce 500 million to 1 billion doses of the vaccine per year, beginning in 2021.