Experimental COVID-19 vaccine safe, induces immune response

SEATTLE — An investigational vaccine designed to protect against COVID-19 appears safe. In healthy adult volunteers enrolled in a phase 1 trial, the vaccine resulted in the production of neutralizing antibodies, according to interim results published today in the New England Journal of Medicine. The study, detailed in “A SARS-CoV-2 mRNA Vaccine — Preliminary Report,” is being led by Lisa A. Jackson, MD, MPH, a senior investigator at Kaiser Permanente Washington Health Research Institute in Seattle.

“The world urgently needs vaccines to protect against COVID-19,” Dr. Jackson said. “We are glad to be able to contribute to these efforts by initiating the first clinical trial of a COVID-19 vaccine, which was developed, produced, and put into a first-in-human clinical trial in record time.”

The experimental vaccine, mRNA-1273, was designed by researchers at the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, in collaboration with the vaccine manufacturer Moderna Inc. of Cambridge, Massachusetts.

The first volunteer received the first vaccine dose on March 16 at Kaiser Permanente Washington Health Research Institute. The interim report details the initial results of the first 45 volunteers aged 18 to 55 enrolled at the study sites in Seattle and at Emory University in Atlanta. Three groups of 15 volunteers received 2 intramuscular injections, 28 days apart, of 25, 100, or 250 micrograms of the investigational vaccine. All volunteers received the first injection; 42 volunteers received both scheduled injections. In April, the trial expanded to enroll adults older than 55, but the newly published results cover only the group of volunteers aged 18 to 55.

No serious adverse events were reported. Fatigue, headache, chills, muscle aches, and pain at the injection site were reported by more than half of the volunteers, with systemic adverse events being more common following the second injection and in those who received the highest vaccine dose. Data on side effects and immune responses at the 3 different vaccine dosages informed the doses used or planned for use in the phase 2 and 3 clinical trials of the investigational vaccine.

The interim analysis includes results of tests measuring levels of vaccine-induced neutralizing antibodies through day 43 after the second injection. Neutralizing antibodies induced by mRNA-1273 are directed at a portion of a viral “spike” protein that the coronavirus uses to bind to and enter human cells. Two doses of the vaccine prompted production of high levels of neutralizing antibody that were above the average values seen in convalescent serum obtained from people with confirmed cases of COVID-19.

A phase 2 clinical trial of mRNA-1273, sponsored by Moderna, began enrollment in late May, and plans are underway to launch a phase 3 efficacy trial in July 2020.

Additional information about the trial design is available at clinicaltrials.gov using the identifier NCT04283461. This trial was supported in part by NIAID grants UM1AI148373 (Kaiser Permanente Washington) and UM1AI148576 (Emory University). The Coalition for Epidemic Preparedness Innovations provided funding for the manufacture of mRNA-1273 phase 1 material.

About the National Institute of Allergy and Infectious Diseases

NIAID conducts and supports research — at NIH, throughout the United States, and worldwide — to study the causes of infectious and immune-mediated diseases and to develop better means of preventing, diagnosing, and treating these illnesses. News releases, fact sheets, and other NIAID-related materials are available on the NIAID website.

About the National Institutes of Health

NIH, the nation's medical research agency, includes 27 institutes and centers and is a component of the Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit the NIH website.

About Kaiser Permanente

Kaiser Permanente is committed to helping shape the future of health care. We are recognized as one of America’s leading health care providers and not-for-profit health plans. Founded in 1945, Kaiser Permanente has a mission to provide high-quality, affordable health care services and to improve the health of our members and the communities we serve. We currently serve 12.4 million members in 8 states and the District of Columbia. Care for members and patients is focused on their total health and guided by their personal Permanente Medical Group physicians, specialists, and team of caregivers. Our expert and caring medical teams are empowered and supported by industry-leading technology advances and tools for health promotion, disease prevention, state-of-the-art care delivery, and world-class chronic disease management. Kaiser Permanente is dedicated to care innovations, clinical research, health education, and the support of community health.

Read more about Kaiser Permanente’s research on vaccines.