A Study of the Effectiveness of Moderna COVID-19 Vaccine

May 22, 2025 updated by: ModernaTX, Inc.

Real-World Study of the Effectiveness of Moderna COVID-19 Vaccine

This is an observational cohort study to evaluate real-world vaccine effectiveness and durability of Moderna COVID-19 vaccine among a diverse population at Kaiser Permanente Southern California (KPSC).

The primary objective of this study is to evaluate the vaccine effectiveness (VE) of receipt of Moderna COVID-19 vaccine in preventing SARS-CoV-2 infection and severe COVID-19 disease.

SARS-CoV-2 infection will be defined as a positive antigen test result as well as a positive molecular diagnostic test among symptomatic or asymptomatic participants or a COVID-19 diagnosis code. Severe COVID-19 disease will be defined as COVID-19 hospitalization or mortality.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

This study utilized electronic healthcare data collected within the Kaiser Permanente Southern California (KPSC) integrated healthcare system which provides care to over 4.6 million individuals. Participants in this study received vaccination and were assessed for study outcomes as part of routine care. Vaccination information and study outcome status was assessed using procedure, diagnostic, and laboratory code information. Medical chart review was conducted to assess the association of severe outcomes (hospitalization and death) with COVID-19 illness.

Analyses assessing absolute vaccine effectiveness will identify participants who receive Moderna COVID vaccine from the KPSC electronic healthcare database and match them to unvaccinated participants based on age, sex, race/ethnicity, and data of vaccination (index date). Vaccinated and unvaccinated participants will then be followed-up in the database for the occurrence of study outcomes. Cox proportional hazards regression will be used to compare the relative risk of study outcomes by vaccination status.

Analyses of relative vaccine effectiveness will identify participants who receive specific dose number and formulation of Moderna COVID vaccine (Group N) from the KPSC electronic healthcare database and match them to a group of vaccinated participants with a different dose/formulation type (i.e. Group n-1). Similar matching criteria will be applied. Both groups will be followed for study outcomes and cox proportional hazards regression will be used to compare the relative risk of study outcomes by vaccination status.

Study Type

Observational

Enrollment (Actual)

927004

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • California
      • Pasadena, California, United States, 91101
        • Kaiser Permanente Southern California

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Probability Sample

Study Population

Participants vaccinated with Moderna COVID-19 vaccine and unvaccinated participants are included in this study.

Description

Inclusion Criteria:

  • Aged ≥18 years at index date (participants aged 6 months through 17 years will also be included after Food and Drug Administration [FDA] authorization to vaccinate younger age groups)
  • KPSC member for ≥12 months prior to index date through 14 days after the index date (allowing a 31-day gap)

Exclusion Criteria:

  • Receipt of a COVID-19 vaccine other than Moderna COVID-19 vaccine prior to or on the index date
  • Receipt of 2 doses of Moderna COVID-19 vaccine <24 days apart for 2-dose exposed cohort
  • Receipt of any COVID-19 vaccine <14 days after the index date
  • No health care utilization and no vaccination from the 2 years prior to the index date through the index date
  • Occurrence of a COVID-19 outcome <14 days after the index date

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Vaccinated Cohort
Participants who receive Moderna COVID-19 vaccine during a pre-specified time frame and meet eligibility criteria will be included in this cohort. Participants will be followed up through Electronic Health Record (EHR) for occurrence of COVID-19 outcomes until the end of the study period, or censoring events (termination of KPSC membership allowing for a 31-day gap, death, receipt of a COVID-19 vaccine).
Biological: mRNA-1273
Sterile liquid for injection
Unexposed Cohort

Participants in this cohort include:

  • Participants who had not received any bivalent dose but had received at least 2 doses of monovalent mRNA COVID-19 vaccine by the index date
  • Participants who never received any COVID-19 vaccine dose by the index date

Participants will be followed up through EHR for occurrence of COVID-19 outcomes until the end of the study period, or censoring events (termination of KPSC membership allowing for a 31-day gap, death, receipt of a COVID-19 vaccine).

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of Participants With SARS-CoV-2 Infection
Time Frame: Up to 3 years
SARS-CoV-2 infection is defined as a positive antigen test result as well as a positive molecular test or a COVID-19 diagnosis code.
Up to 3 years
Number of Participants With Severe COVID-19 Disease
Time Frame: Up to 3 years
Severe COVID-19 disease includes COVID-19 hospitalization (hospitalization with a SARS-CoV-2 positive test or a COVID-19 diagnosis, or a hospitalization occurring ≤7 days after a SARS-CoV-2 positive test, with chart review to confirm severe COVID-19 symptoms) and COVID-19 mortality (death during COVID-19 hospitalization).
Up to 3 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

ModernaTX, Inc.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 18, 2020

Primary Completion (Actual)

November 17, 2023

Study Completion (Actual)

November 17, 2023

Study Registration Dates

First Submitted

July 5, 2023

First Submitted That Met QC Criteria

July 5, 2023

First Posted (Actual)

July 6, 2023

Study Record Updates

Last Update Posted (Actual)

May 28, 2025

Last Update Submitted That Met QC Criteria

May 22, 2025

Last Verified

May 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • mRNA-1273-P901

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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