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A Study to Evaluate Efficacy, Safety, and Immunogenicity of mRNA-1273 Vaccine to Prevent COVID-19

Clinical Trial Details

Coronaviruses (CoV) are a large family of viruses that cause illness ranging from the common cold to more severe diseases, such as Middle East respiratory syndrome and SARS-CoV. Coronaviruses are zoonotic, meaning they are transmitted between animals and people.

There is currently no vaccine that has been shown to be effective against SARS-CoV-2. Therefore, there is an urgent public health need for rapid development of novel interventions to prevent the spread of this disease. This study is testing the mRNA-1273 study vaccine at a dose of 100 micrograms (µg). The mRNA-1273 study vaccine is intended to boost the immune system to produce enough antibodies against SARS-CoV-2; so, in case of an exposure, the virus does not cause illness.

The main purpose of this study is to understand if mRNA-1273 can prevent COVID-19 and to understand the safety of the mRNA-1273 study vaccine. 

The study length is 25 months and includes approximately 6 visits to the clinic and 25 phone calls. If you chose to participate in this study, you will receive 2 injections of study vaccine or placebo given about 1 month apart. All subjects will be randomly assigned to receive two doses of 100 µg [microgram] of an experimental study vaccine called “mRNA-1273” or a placebo (a saline injection that contains no active ingredients). Each subject will receive an injection of mRNA-1273 100 µg [microgram] or placebo at Visit 1 (Day 1) and at Visit 2 (Day 29). This random assignment (like flipping a coin) will be a 1:1 ratio.

For those interested in joining the study, please visit our registry at: COVID-19 Prevention Network (CoVPN) Screening Registry.

Key Eligibility: 

Inclusion Criteria

  • Adults 18 or older who are at high risk of SARS-CoV-2 infection, defined as adults whose locations or circumstances put them at appreciable risk of exposure to SARS-CoV-2 and COVID-19
  • Healthy adults or adults with pre-existing medical conditions who are in stable condition. A stable medical condition is defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 3 months before enrollment.

Exclusion Criteria

  • Known history of SARS-CoV-2 infection
  • Prior administration of an investigational coronavirus vaccine or current participation in another interventional study to prevent or treat COVID-19
  • Adults who are pregnant or breastfeeding
  • Immunosuppressive or immunodeficient state, asplenia, recurrent severe infections (HIV-positive participants on stable antiretroviral therapy are not excluded.)

Study contact by location

Upper East Side - Manhattan


CCTU Covid Team

Chelsea - Manhattan

Chelsea Clinical Trial Location


CCTU Covid Team

Primary Investigator(s)

Protocol ID(s)

Weill Cornell Medicine IRB #:




Open to Enrollment

Age Group