Moderna Therapeutics has announced that the company has launched a phase 3 clinical trial to evaluate the effectiveness of the mRNA-1273 investigational COVID-19 vaccine to prevent symptomatic coronavirus disease in adults.
The vaccine was co-developed by the biotechnology company Moderna, Inc., and the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.
NIAID scientists developed the stabilised SARS-CoV-2 spike immunogen (S-2P), the protein found on the surface of the virus facilitating entry into a cell. The mRNA-1273 uses the mRNA (messenger RNA) delivery platform to encode for an S-2P immunogen. The investigational vaccine directs the body’s cells to express the spike protein to elicit a broad immune response.
The trial, which will be conducted at various clinical research sites in the US, is expected to enroll approximately 30,000 adult volunteers who do not have COVID-19.
Trial volunteers will receive two intramuscular injections approximately 28 days apart. Participants will be randomly assigned 1:1 to receive either two 100 microgram (mcg) injections of mRNA-1273 or two shots of a saline placebo.
Volunteers will be asked to provide a nasopharyngeal swab and a blood sample at an initial screening visit and additional blood samples at specified time points after each vaccination and over the two years following the second vaccination.
The phase 1 clinical trial showed the candidate vaccine to be safe, generally well-tolerated and capable of inducing antibodies with high levels of virus-neutralising activity. Moderna initiated phase 2 testing of the vaccine in May.
“Results from early-stage clinical testing indicate the investigational mRNA-1273 vaccine is safe and immunogenic, supporting the initiation of phase 3 clinical trial. This scientifically rigorous, randomized, placebo-controlled trial is designed to determine if the vaccine can prevent COVID-19 and for how long such protection may last,” said NIAID Director Anthony S. Fauci, M.D.
As secondary goals, the phase3 trial also aims to study whether the vaccine can prevent severe COVID-19 or laboratory-confirmed SARS-CoV-2 infection with or without disease symptoms, said the researchers.
Scientists will examine blood samples to detect and quantify immune responses to SARS-CoV-2 over the 2 years.