Two studies based on phase 3 clinical trials published yesterday in the New England Journal of Medicine show promising results for two novel COVID-19 vaccine platforms—a plant-based coronavirus-like particle vaccine, and a receptor-binding domain (RBD)–dimer-based vaccine.And neither vaccine requires extreme cold chain storage, which makes them appealing candidates for low- and middle-income countries, a key component of global COVID-19 vaccination efforts.Vaccines perform well despite variantsThe first vaccine is a plant-based particle vaccine, developed by Medicago/GSK, and was tested on participants in Argentina, Brazil, Canada, Mexico, the United Kingdom, and the United States from Mar 15 to Sep 2, 2021.The vaccine, CoVLP, was administered in two shots 21 days apart, and results were compared to placebo.
The study continued until at least 160 COVID-19 cases were detected in participants at least 7 days following the second dose of vaccine.A total of 24,141 volunteers participated in the trial.
Vaccine efficacy was 69.5% (95% confidence interval [CI], 56.7% to 78.8%) against any symptomatic COVID-19 caused by five variants that were identified by sequencing, the authors found.
Results were even stronger for efficacy against moderate-to-severe disease, at 78.8% (95% CI, 55.8% to 90.8%).No severe cases or deaths were recorded in the vaccine group.