Understanding Moderna’s Covid-19 Vaccine Trial Results

New press release data reveals a broadly effective vaccine that could be approved by the end of the year

Image: The New York Times

As people return to work after a holiday weekend, another bright spot in the race to develop a Covid-19 vaccine has emerged. In a press release, pharmaceutical company Moderna released the final results of its phase three COVE trial, indicating that its experimental mRNA-1273 vaccine is more than 94% effective against Covid-19.

The firm has begun the process of approval in various countries including the U.S. A meeting with the Food and Drug Administration’s Vaccine and Related Biological Products Advisory Committee is set for December 17. This meeting will evaluate the safety data of the vaccine — a key hurdle in the FDA’s approval process.

What does the data show?

mRNA-1273 is effective in preventing Covid-19 infections

  • Participants: 30,000
  • Total Covid-19 cases: 196
  • Total cases in the placebo group: 185
  • Total cases in the vaccine group: 11

The results of this study revealed an efficacy rate of 94.1%. These results were consistent across a range of demographics including age, race, and gender.

mRNA-1273 is effective in preventing severe Covid-19 cases

  • Total number of severe Covid-19 cases: 30
  • Total number of severe cases in the vaccine group: 0

Severe Covid-19 cases were defined in the clinical trial protocol as:

  • Vitals: respiratory rate ≥ 30/minute, heart rate ≥ 125 bpm, oxygen saturation ≤ 93% on room air
  • Evidence of respiratory failure, acute respiratory distress syndrome (ARDS) or shock OR
  • Acute renal failure OR
  • Admission to ICU or death
  • Acute respiratory distress syndrome (ARDS) or shock or acute renal failure or admission to ICU or death

These results reveal that none of the vaccinated group participants contracted severe forms of Covid-19.

One of the main goals of phase three trials is to determine the safety of a vaccine. Moderna’s results continue to show that this vaccine is well-tolerated and safe. Some reported adverse effects of the vaccine were mild symptoms common in most vaccines including:

  • Pain at the injection site
  • Pain at the injection site
  • Muscle and joint aches
  • Muscle and joint aches
  • Headaches

It is important to note that these are common and expected adverse effects of most vaccines. These effects are self-limiting and will go away within a day or so after the injection.

Promising results, but there are miles to go

The findings in the COVE trial may turn out to be a positive endnote to a very challenging year. Many scientists are heralding today’s results as a truly monumental and historic achievement.

Source: Twitter, Eric Topol

Despite this uplifting news, the fact remains that new Covid-19 cases are at all-time highs with death rates continuing to climb. At the time of this writing, over 260,000 people had lost their lives to this virus.

FDA emergency use authorization (EUA) allows for the rush use of drugs and vaccines. The earliest vaccines could roll out just before Christmas at the earliest. EUA will likely prioritize vaccinations for health care workers, police and fire staff, and other essential workers, including nursing home staff. Vaccination for the general public will likely not be available until late spring.

Until then, most authorities urge that social distancing, limiting of gathering and travel, and use of masks when in public are still our most powerful tools in slowing the spread of Covid-19.

More information on the mRNA-1273 vaccine

Medical student, molecular biologist and educator. I write about science and medicine.

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