On Aug. 31, 2020, a multi-site, Phase 3 clinical trial evaluating an investigational COVID-19 vaccine known as AZD1222 was launched. The trial includes enrollment of approximately 30,000 adult volunteers at 80 sites in the U.S. to evaluate if the candidate vaccine can prevent symptomatic coronavirus disease 2019 (COVID-19). AstraZeneca is leading the trial as regulatory sponsor. The National Institute of Allergy and Infectious Diseases and the Biomedical Advanced Research and Development Authority provided funding support for the trial.

The Phase 3 trial is being implemented as part of Operation Warp Speed, a multi-agency collaboration led by HHS that aims to accelerate the development, manufacturing and distribution of medical countermeasures for COVID-19. The Accelerating COVID-19 Therapeutic Interventions and Vaccines (ACTIV) public-private partnership also guided the development of the trial protocol to ensure a coordinated approach across multiple vaccine efficacy trials. NIH experts have emphasized the importance of a harmonized process to generate data for multiple investigational vaccines in parallel to assess the relative effectiveness of each.

Oxford University’s Jenner Institute and Oxford Vaccine Group developed AZD1222. The candidate vaccine was licensed to AstraZeneca for further development. The vaccine uses a non-replicating chimpanzee adenovirus to deliver a SARS-CoV-2 spike protein to induce an immune response. SARS-CoV-2 is the virus that causes COVID-19.

Scientists at NIAID’s Rocky Mountain Laboratories (RML), based in Hamilton, Montana, conducted a preclinical study of AZD1222. Their findings — published in Nature — indicate the candidate vaccine rapidly induced immune responses against SARS-CoV-2 in mice and rhesus macaques. A single dose of the vaccine protected six rhesus macaques from pneumonia caused by the virus. Based on the RML data, a Phase 1 trial of the candidate vaccine began on April 23 in healthy volunteers in the U.K. Investigators recently reported promising results in The Lancet. Currently, the vaccine candidate is being evaluated in Phase 2/3 trials in the U.K. and Brazil and in a Phase 1/2 trial in South Africa.

The NIAID COVID-19 Prevention Network (CoVPN) will participate in the Phase 3 clinical trial of AZD1222 in the U.S. The CoVPN is composed of existing NIAID-supported clinical research networks with infectious disease expertise and is designed for efficient and thorough evaluation of vaccine candidates and monoclonal antibodies for the prevention of COVID-19.