General Information

The Moderna COVID-19 Vaccine (mRNA-1273) is an mRNA vaccine against COVID-19 encoding for a prefusion stabilized form of the Spike (S) protein. Messenger RNA (mRNA) is genetic material. The vaccine contains a small piece of the SARS-CoV-2 virus’s mRNA that instructs cells in the body to make the virus’s distinctive “spike” protein. After a person receives this vaccine, their body produces copies of the spike protein, which does not cause disease, but triggers the immune system to learn to react defensively, producing an immune response against SARS-CoV-2.   

The Moderna COVID-19 Vaccine is specifically indicated for use in adults 18 years of age and older to prevent COVID-19 infection.

The Moderna COVID-19 vaccine is supplied as  a suspension for intramuscular injection administered as a series of two doses (0.5 mL each) 1 month apart.

Side Effects

Adverse effects associated with the use of the Moderna COVID-19 vaccine may include, but are not limited to, the following:

• pain at the injection site
• fatigue
• headache
• myalgia
• arthralgia
• chills
• nausea/vomiting
• axillary swelling/tenderness
• fever
• swelling at the injection site
• erythema at the injection site

The Moderna COVID-19 Vaccine should not be administered to individuals with a known history of severe allergic reaction (e.g., anaphylaxis) to any component of the Moderna COVID-19 Vaccine. Appropriate medical treatment to manage immediate allergic reactions must be immediately available in the event an acute anaphylactic reaction occurs following administration of the Moderna COVID-19 Vaccine. 

Clinical Trial Results

The Moderna COVID-19 vaccine was granted Emergency Use Authorization based on available data providing clear evidence that the Moderna COVID-19 vaccine may be effective in preventing COVID-19. The data also support that the known and potential benefits outweigh the known and potential risks. The FDA expects Moderna to continue clinical trials to obtain additional safety and effectiveness information and pursue approval (licensure).

Emergency Use Authorization was based on the Phase 3 COVE trial, a randomized, 1:1 placebo-controlled study testing the Moderna COVID-19 Vaccine at the 100 µg dose level in 30,000 participants in the U.S., ages 18 and older. The primary endpoint is the prevention of symptomatic COVID-19 disease. Key secondary endpoints include prevention of severe COVID-19 disease and prevention of infection by SARS-CoV-2. The FDA’s analysis of the efficacy data from 28,207 participants 18 years of age and older without evidence of SARS-CoV-2 infection prior to dose 1 confirms the vaccine was 94.1% effective in preventing COVID-19 occurring at least 14 days after the second dose (with 11 COVID-19 cases in the vaccine group compared to 185 COVID19 cases in the placebo group). In this final scheduled analysis participants had been followed for a median of 9 weeks following the second dose. This result is consistent with that obtained from an interim analysis of efficacy conducted after these participants had been followed for a median of 7 weeks after the second dose (vaccine efficacy 94.5%).