Many people are asking, 'Well why do we have to test the vaccines? Why don't we just make the vaccines and give them to people?' Well the world has learned many lessons in the mass use of vaccines and there's only one thing more dangerous than a bad virus, and that's a bad vaccine, we have to be very, very, very careful in developing any product that we're going to inject into potentially most of the world population. We have to be very, very, very careful that we first do no harm. So that's why people are being careful.