There are some chemical differences between the curvac one and the ones from feizer, bionte and maderna that many scientists are looking at to possibly explain the results. One of those key differences is in one particular base of the m r and a. Could you tell us what the difference is there yet? It's just really a small chemical tweak to one of the four bases. Normally we talk about a, c, t g but m na uses one different building block. We just call it u. And around two thousand and five some researchers at the university of pennsylvania discovered that instead of using normal u, you use slightly modified u. This helps make the r n a