Final Tally of CureVac Covid Candidate Confirms 48% Efficacy

02.07.2021 - Definitive results from CureVac’s 40,000-subject international Phase 2b/3 trial with its mRNA-based Covid-19 vaccine candidate, CVnCoV, have confirmed an earlier finding that it is only about 48% effective in preventing infection of any severity across the “unprecedented” 15 strains of the virus encountered during the tests with participants in Latin America and Europe.

Despite the weaker than expected showing, the German biotech, in which the German federal government holds a minority stake, said it will nevertheless proceed with its application to the European Medicines Agency (EMA) for conditional marketing approval. Simultaneously it plans to continue the clinical study to provide follow-up analyses for trial participants.

CEO Franz-Werner Haas said the candidate demonstrated “a strong public health value in fully protecting study participants in the age group of 18 to 60 against hospitalization or death and 77% against moderate and severe disease.”  The efficacy score in this category was 53% on average against disease of any severity and across all 15 identified strains. 

In the same group, CVnCov was shown to provide 100% protection against hospitalization or death, though in trial participants older than 60, who represented 9% of the analyzed cases, available data was deemed insufficient to determine efficacy.

Haas said the company believes this efficacy profile “will be an important contribution to help manage the Covid-19 pandemic and the dynamic variant spread.” CureVac, he added, is “confident” its study offers clinically relevant data regarding the effect of emerging variants. As regards safety, the data provided to the European Medicines Agency (EMA) for review reportedly confirm the favorable profile of CVnCoV in all age groups.

Of the 204 cases sequenced to identify the variant causing the infection. around 86% were found to be caused by Covid Variants of Concern and Variants of Interest, including the Lambda strain first identified in Peru. Only 3% of cases were attributable to the original SARS-CoV-2 virus.

Alongside the first-generation CVnCoV, the biotech is developing second-generation COVID-19 vaccine candidates together with UK drugmaker Glaxo SmithKline. These candidates, it said, are based on new mRNA backbones and include potential variants in multivalent vaccine formats as well as combination vaccines for potential protection against multiple infectious diseases in single injection.

CureVac and GSK expect to progress the second-generation vaccine candidate into clinical testing in the third quarter of this year, with the goal of introducing the vaccine in 2022, subject to regulatory approval.

Author: Dede Williams, Freelance Journalist