ABC News Corona Virus Health and Science

Coronavirus vaccine tests show promise in early human testing: Study

Phase 2 testing will begin shortly, phase 3 slated for July.

The biotech company researching a coronavirus vaccine released early results of its phase 1 testing Monday, saying it found promising results so far.

Moderna, which conducted the first human trials, said its vaccine, mRNA-1273, was "generally safe and well-tolerated" in its clinical trials of patients, ages 18-55. The study, which is led by the National Institute of Allergy and Infectious Diseases (NIAID), tested three doses: 25 mcg, 100 mcg and 250 mcg.

Two weeks after patients received the final dose at the 25 and 100 mcg levels, eight saw their antibody levels rise to about the same level as patients who already recovered from COVID-19, according to the report.

Moderna said three patients who were given that the highest dose -- 250 mg -- showed short-lived flu-like symptoms, which they say is common in vaccines.

The report also tested the vaccine on mice and found that it prevented viral replication in the animals' lungs.

Tune into ABC at 1 p.m. ET and ABC News Live at 4 p.m. ET every weekday for special coverage of the novel coronavirus with the full ABC News team, including the latest news, context and analysis.

"We believe these two data sets represent an important step forward," Stéphane Bancel, CEO of Moderna, said in a conference call with reporters.

The success of the two lower doses in tests so far could be promising for future vaccine development since lower volumes per dose would mean that there would be more doses for everyone.

The company said it would start phase 2 trials soon and research two dose levels, 50 mcg and 100 mcg. It is slated to start phase 3 in July where Moderna will recruit adults who are most at risk for infection.

More than 100 vaccines are being studied for COVID-19 infection, and at least eight of these, including Moderna's, have already progressed to human studies.

This report was featured in the Tuesday, May 19, 2020, episode of “Start Here,” ABC News’ daily news podcast.

"Start Here" offers a straightforward look at the day's top stories in 20 minutes. Listen for free every weekday on Apple Podcasts, Google Podcasts, Spotify, the ABC News app or wherever you get your podcasts.

What to know about Coronavirus:

  • How it started and how to protect yourself: Coronavirus explained
  • What to do if you have symptoms: Coronavirus symptoms
  • Tracking the spread in the US and Worldwide: Coronavirus map
  • Top Stories

    Top Stories

    Top Stories

    Top Stories

    ABC News Live

    ABC News Live

    24/7 coverage of breaking news and live events