In our world, billions of people suffer from contagion, however, only part of them can be prevented by proper vaccine. Many disadvantages limit the usage of traditional vaccine especially in developing countries. This year, our project focused on a revolutionary vaccine delivery. We chose bacillus subtilis as chassis to establish a transdermal vaccine fresh secreting band-aid which consists of four engineering b.subtilis, each of them carries a gene circuit independently. By using an excellent transdermal peptide TD1, three of them could express a serious of fusion proteins(antigen, 2 kinds of adjuvants) which could penetrating the skin and work as traditional vaccine molecule. The fourth type of them is our “reporter” which could notify users whether the band-aid works well and when they could stick or tear off the patch. Moreover we designed a reliable suicide system in bacillus subtilis for the very first time in iGEM. So it would be ok if our users tear patches off and throw them away. Cheap and convenient, we just create a world without needle.

With the support of TD-1, a special polypeptide, which can greatly facilitate macromolecule transdermal delivery through intact skin, we construct three different fuctional engineered bacillus subtilis; besides, we design a kill switch in the fouth type B.subtilis to ensure biosafety.