Moderna says test results for possible COVID-19 vaccine 'positive'

A pedestrian walks past a bar established in 1933 after Los Angeles County officials closed it for the second time following a spike in COVID-19 cases in Los Angeles on August 10. Photo by Jim Ruymen/UPI | License Photo

May 18 (UPI) -- U.S. biotechnology firm Moderna announced Monday that early test results for a possible coronavirus vaccine are positive and indicate a "potential to prevent" COVID-19.

Moderna said first results of a stage-one clinical trial show its vaccine candidate "mRNA-1273" succeeded in producing antibodies to attack the SARS-CoV-2 coronavirus in all 45 test subjects, in quantities "of the magnitude caused by natural infection."


The trial, which is being done in a partnership with the National Institute of Allergy and Infectious Diseases at the National Institutes of Health, has been underway for weeks and is one of many worldwide that could ultimately produce a COVID-19 vaccine.

Moderna said its vaccine candidate was found to produce antibody levels in participants on levels similar or better than convalescent plasma and has proven "generally safe and well tolerated."

"These interim Phase 1 data, while early, demonstrate that vaccination with mRNA-1273 elicits an immune response," Moderna Chief Medical Officer Tal Zaks said in a statement.

"[The vaccine] provided full protection against viral replication in the lungs in a mouse challenge model."

Zaks said the stage-one results, combined with those of a pre-clinical study, substantiate Moderna's belief that mRNA-1273 has the potential to "prevent COVID-19 disease" and advance plans to "select a dose for pivotal trials."


"The Moderna team continues to focus on moving as fast as safely possible to start our pivotal Phase 3 study in July and, if successful, file a [biologics license application]," added Moderna CEO Stéphane Bancel. "We are investing to scale up manufacturing so we can maximize the number of doses we can produce to help protect as many people as we can."

U.S. regulators cleared mRNA-1273 for a second phase earlier this month, and Zaks said it will begin "shortly."

Earlier this month, U.S. pharmaceutical giant Pfizer said it has started testing a vaccine candidate on human subjects in the United States. Other possible vaccines in the clinical stage are also being developed elsewhere in the United States, as well as China and Britain.

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