A final analysis of a phase 2b/3 study of CureVac’s COVID-19 vaccine candidate CVnCoV demonstrated 48% overall efficacy, only a slight improvement on the previously reported 47% efficacy.
In June, CureVac reported that its first-generation mRNA vaccine candidate proved to only be 47% effective following an interim analysis of data from the pivotal HERALD study of approximately 40,000 participants.
In the final analysis, CureVac noted a higher overall efficacy among participants who are 18 to 60 years of age, with an efficacy of 53% against disease of any severity across all 15 identified variants in this population.
Protection against moderate-to-severe disease was found to be 77% effective, with the vaccine providing 100% protection against hospitalisation or death in the same age group.
For participants over 60 years of age – representing 9% of the analysed cases – the available data did not enable a statistically significant determination of efficacy, CureVac said in a statement.
Out of the 228 cases assessed in the final analysis, 204 were sequenced to identify the specific variant that caused the infection.
Investigators found that approximately 86% of these cases were caused by variants of concern and variants of interest. Only 3% of cases were attributable to the original SARS-CoV-2 virus, while the remaining 11% were caused by ‘less explored’ strains.
The study is set to continue to complete follow-up analyses for trial participants, while the available data has already been communicated to the European Medicines Agency (EMA).
“In the current context of an increasingly diverse environment of COVID-19 variants, and with very little residual prevalence of the original strain, we are confident that the HERALD study offers clinically relevant data regarding the effect of emerging variants on vaccine efficacy,” said Franz-Werner Haas, chief executive officer of CureVac.
Along with its first-generation mRNA COVID-19 vaccine, CureVac has partnered with GlaxoSmithKline (GSK) to develop the next generation of mRNA-based COVID-19 vaccines.
The deal is focused on developing a novel mRNA-based COVID-19 vaccine candidate, by using multivalent and monovalent approaches.
The next-generation vaccine will aim to offer broader protection against newly emerging variants, which have been reported to have the potential to reduce the efficacy of first-generation mRNA jabs.