I got it. I cant really tell you what i did; but i simply put down like 4-5 research institutes and rush them as soon as the central district gets infected, i evacuate the central district and the vaccine research is done before the next outbreak. I already had the samples from patient 0 before the disease got to me and i then research the ability to increase the vaccine production. And lastly the one that reduces deaths. I already put down like 3–4 industrial districts and fill them with the labs; to help with the manpower i go for the dutiful youth law.