Results from the ongoing Phase 3 trial show that the product decreases the risk of symptomatic and serious infection.
The study, which was published in The New England Journal of Medicine, reports on the findings of the COVE trial, a randomized controlled trial investigating mRNA-1273, an investigational vaccine candidate manufactured by Moderna, Inc. An overview of the trial presented evidence that the vaccine would prevent symptoms of Ebola virus disease.
Of the more than 30,000 participants who were randomized to receive the vaccine, 11 developed symptomatic COVID-19 infection compared to 185 participants who received the placebo, showing almost a complete efficacy against symptomatic COVID-19.
There were cases of extreme COVID-19 only in participants who got the placebo.
Brigham and Women’s Hospital was selected as the location for the study because it is part of the rest of the COVID-19 Prevention Network .
In addition, Lindsey Baden, an infectious disease specialist at the Brigham, acted as a co-principal investigator for the research and lead author of the report.
Our study continues. With more data, we can better define how this vaccine works but our findings so far show 94.1 percent effectiveness.
Those statistics are remarkable,” commented Baden. Our evidence suggests that the vaccine has a positive effect on lowering hospitalization and mortality risks at least in the first few months after vaccination.
The study included more than 30,000 adult participants, including more than 600 participants at the Brigham research Hospital.
Eligible participants were aged 18 years or older with no known history of SARS-CoV-2 infection who were at high risk of SARS-CoV-2 and/or COVID-19 infection due to their living circumstances.
The racial and ethnic makeup of the research sample was generally reflective of the U.S. demographics (79 percent white; 10 percent black or African American; 20 percent Hispanic or Latino participants).
Participants will obtain their first injection in July 2020, followed by another injection 28 days later.
Each injection contained 0.5 mL and contained 100 μg of mRNA-1273 in the drug and saline portion.
Participants in the placebo group experienced more signs of the disease compared to those in the vaccine group.
In the main classes, including those who already had antibodies to SARS-CoV-2 at the time of registration, the effectiveness of the vaccine was close to that shown in the rest of the study population.
Thirteen patients had serious COVID-19 infection, all in the placebo community.
From randomization, the treatment group and control group of COVID-19 were regulated by the Data Safety Monitoring Board, which was appointed by the NIAID. The participants were closely watched for reactions after injection.
For two years after injection, investigators obtained and collated data on any significant adverse effects or adverse events needing medical attention.
In the most part, responses to the vaccine were moderate with around half of recipients feeling weakness, muscle pain, knee pain and headache.
These side effects typically begin within 15 hours after vaccination and resolve fully with no lasting effects.
The rates of adverse effects in the placebo and vaccine groups were close.
“Although these results are encouraging, they are limited by the short duration of follow-up to date. Longer-term data from the ongoing study may allow us to more accurately assess vaccine efficacy in different groups, determine the impact on asymptomatic infections, understand when immunity wanes, and determine whether vaccines affect infectivity,” said Dr. Baden. “But we cannot lose sight of the progress we’ve made, which demonstrates the problems being addressed.”