Tests that can not only detect the presence of antibodies to Covid-19 in a person’s blood, but also measure their levels, are starting to be considered a new frontier in antibody testing. On Friday Roche launched just such a test in the EU. Crucially, the new Elecsys Anti-Sars-CoV-2 S test detects antibodies to the coronavirus’s spike protein’s receptor binding domain, meaning it could be used to assess the efficacy of most vaccines in development, as well as convalescent plasma therapy. Roche is also seeking emergency use authorisation from the FDA for the test; so far Siemens Healthineers remains the only group to have US authorisation for similar assays, though Healthineers’ are semi-quantitative, meaning they estimate the antibody levels rather than directly measuring them. This new test is the twelfth Roche has developed for Covid-19; its portfolio includes molecular and antibody tests as well as one that measures interleukin-6 levels.