Filenews 17 June 2021
The German biopharmaceutical company CureVac has disappointingly announced preliminary results of its clinical trial of its vaccine against Covid-19. Her mRNA vaccine had efficacy of only 47%, one of the lowest announced by manufacturers of anti-coronavirus vaccines.
The PHASE 2b/3 HERALD trial, carried out on approximately 40,000 volunteers in ten South American and European countries, will continue as new Covid-19 cases gradually appear among participants. A final analysis of effectiveness is expected in two to three weeks, according to the New York Times and Reuters.
"We are moving quickly for the final announcement. We are still planning to apply for approval," said the company's chief executive Franz-Werner Haa, but one vaccine expert, Jacob Kirkegor of the Peterson Institute for International Economics in Washington, spoke of "devastating" results for the company.
The company initially intends to seek approval from the European Medicines Agency (EMA), as the European Union has agreed with CureVac to buy 405 million doses of the vaccine if approved. Now it is doubtful whether this order will proceed. Independent experts find the future of the vaccine difficult, as even if the effectiveness is eventually announced to be somewhat greater, it will hardly reach the level of other vaccines.
"Its effectiveness is not going to change dramatically," estimated biostatistics expert Dr. Natalie Dean of the University of Florida. It is recalled that the other mRNA vaccines of Moderna and Pfizer/BioNTech have an efficacy of around 95%.
The news disappointed those who had hoped Curevac could supply modern-tech vaccines to middle- and low-income countries, as its own vaccine has been kept in a simple refrigerator for months, while it is also cheaper.
CureVac's preliminary results were announced after the company had data on 135 volunteers who fell ill with Covid-19. An independent panel compared the number of patients who had been vaccinated with those who had had a plasibo vaccine and showed a 47% efficacy against the disease (light or heavy). By comparison, the flu vaccine has around 40% to 60%. Both the World Health Organization and the U.S. Food and Drug Administration (FDA) have set 50% as a minimum of acceptable efficacy for Covid-19 vaccines amid a pandemic, with at least 70% considered desirable.
The low efficacy surprised scientists, given that the CureVac vaccine is mRNA and in addition had shown promising results in animal experiments and early human trials. "It's about scratching one's head," Dean said.
The company's chief executive Dr. Haa attributed it to the large number of new variants of corovirus in the countries where the vaccine was tested. Of the 124 cases of Covid-19 in the clinical trial, which were genetically tested, only one was due to the original "Chinese" strain. 21% of the samples analysed came from the new most contagious Lambda variant that appeared in Peru.
As Ha'a said, this should be a "bell of danger" to the threat posed by the new variants, in terms of the effectiveness of vaccines in general. "This is definitely a new Covid reality," he said. He also said that, based on preliminary results, the CureVac vaccine provides less protection for the over-60s than for younger people.
However, although the high efficacy of 95% of other mRNA vaccines had resulted from clinical trials prior to the onset of variants, the most recent data from the real world, where new strains of corovirus are now circulating, show a relatively small decrease in the effectiveness of Moderna and Pfizer/BioNTech vaccines.
Shares in the Tibingen-based company, which planned to produce up to 300 million instalments in 2021 and one billion in 2022, suffered a nearly 51% plunge in the stock market after the bad news.
