A vaccine candidate developed by the German company CureVac has suffered a setback after late-stage trial data showed it was just 47 percent effective against COVID-19. 

Virus variants cause dip in CureVac vaccine’s efficacy

The Tübingen-based company announced the disappointing results in a statement on Wednesday: “CVnCoV demonstrated an interim vaccine efficacy of 47 percent against COVID-19 disease of any severity and did not meet prescribed statistical success criteria.” The World Health Organisation considers vaccines with an efficacy above 50 percent worth using - which puts the CureVac candidate a few crucial points short. 

CureVac said the setback was down to the “unprecedented context of at least 13 variants circulating within the study population subset assessed”. CEO Franz-Werner Haas added that, among trial participants, there was only one case of COVID-19 caused by the “original variant” for which the CureVac and its study protocol were designed. 

However, Haas believes this demonstrates “the importance of developing next-generation vaccines as new virus variants continue to emerge.” 

CureVac suffers multiple setbacks

The setback comes shortly after a delay to CureVac’s late-stage trial, which was held up while it waited for enough of its 40.000 participants in Europe and Latin America to catch coronavirus - something which proved a challenge amid dwindling infection rates. 

CureVac, which works together with fellow German company Bayer, was once considered one of the great hopes in the global vaccine race. Just a year ago, the German state invested around 300 million euros in the company. But while countries all around the world have been administering its competitors’ vaccines now for months, CureVac is still collecting data. 

It initially expected to seek approval for its jab in the EU by the second quarter of 2021, with Germany pencilling in 1,4 million doses by the end of June, but this date has now been pushed back to at least August. According to the German newspaper Mannheimer Morgen, the German government is no longer counting on CureVac to play a role in the current vaccination drive. In the wake of the news, the company’s stock price dropped by more than half on Thursday.

CureVac vaccine does have some advantages

Like the highly-effective vaccines developed in record time by rival companies BioNTech / Pfizer and Moderna, CureVac’s jab uses novel mRNA technology. Despite being something of a tortoise in the global vaccine race, CureVac maintains that its vaccine has some distinct advantages over its competitors. 

For one, it can be kept at standard refrigeration temperatures, unlike the Pfizer and Moderna vaccines, which require ultra-cold storage. It also uses a lower dosage, meaning it can be mass-produced more quickly and cheaply. 

CureVac will conduct a final analysis in the next few weeks - and Haas says the effectiveness could still change. The company is also now working on a second generation coronavirus vaccine candidate in partnership with the British pharmaceutical company GlaxoSmithKline. A clinical trial should begin in the third quarter and a market launch is planned for the coming year.