Two COVID-19 vaccines, one from Moderna and one from Pfizer, have been given emergency approval from the FDA. The two vaccines are similar in the technology they use, and the timeline of their development, but also differ in several ways.
Here's a breakdown of some similarities and differences between the two vaccines:
What's the same:
- Both showed very high efficacy rates in clinical trials. Moderna's vaccine was 94.1 percent effective in a 30,000-person trial, and Pfizer's was 95 percent effective in a 38,000-person trial.
- They both require two doses. Pfizer's vaccine requires two 30-microgram doses given 21 days apart and Moderna's requires two 100-microgram doses given 28 days apart.
- Both vaccines use mRNA technology, which seeks to mimic infection in the body by carrying the genetic instructions for cells to produce antibodies that fight COVID-19. But the mRNA in the two vaccines have slightly different structures, which is why they have different storage and handling characteristics, according to CNN.
What's different:
- Pfizer's vaccine is authorized for use in people 16 years and older, while Moderna's is authorized for those 18 years and older. Pfizer tested its vaccine in younger people than Moderna did.
- Pfizer's vaccine must be stored at minus 94 degrees fahrenheit, while Moderna's must be stored at around minus 4 degrees Fahrenheit, which is the temperature of a home freezer.
- Moderna's vaccine can be kept in a refrigerator for 30 days before it expires, while Pfizer's can only be kept in a refrigerator for five days before it expires.
- Moderna developed its vaccine in a partnership with the National Institute of Allergy and Infectious Diseases, a division of the National Institutes of Health, while Pfizer developed its vaccine independently.