Early analysis suggests that another mRNA vaccine is safe, but its effectiveness isn’t yet known.

The New York Times, May 28, 2021

The German company CureVac said on Friday that its Covid-19 vaccine had passed its first interim analysis, but that it was not yet ready to share data on how well it protects against infection. The shot could be cheaper and more accessible to low-income countries that lack vaccines.

The company said that an independent Data Safety Monitoring Board found no safety concerns. But the board did not share any efficacy data, suggesting that it’s not yet clear just how much protection the vaccine provides.

“The trial will continue to collect sufficient data in order to conduct statistically significant efficacy analysis,” the company said in its statement.

The CureVac vaccine is based on mRNA technology, like the ones developed by Moderna and Pfizer-BioNTech. Those vaccines are in use in the United States and the European Union and have proved to be highly effective, boosting hopes that CureVac’s might provide similarly strong protection against Covid-19.

CureVac’s vaccine might have some advantages over the other mRNA vaccines. It can be stored in a refrigerator for at least three months at 41 degrees Fahrenheit, and it can sit for 24 hours at room temperature before it is used.

In their initial formulations, the Moderna and Pfizer-BioNTech vaccines had to be kept in a deep freeze. Both companies have been tinkering with their recipes to make their vaccines more stable at warmer temperatures, which may broaden their use in poorer countries where freezing poses a challenge.

CureVac’s doses might also turn out to be cheaper than the others. Public Citizen, a consumer advocacy organization, released a report Wednesday from researchers at Imperial College London, estimating the costs of producing enough RNA vaccines to provide herd immunity in low- and middle-income countries. Researchers found that it would cost $23 billion to make 8 billion doses of Pfizer-BioNTech, $9 billion for Moderna and just $4 billion for CureVac.

Last year, the company’s vaccine had promising results when used on animals. By December they had launched their final clinical trial, recruiting 40,000 volunteers in 10 countries in Latin America and Europe. On Wednesday, CureVac indicated that further information about its vaccine trial would arrive by the end of June.