Slight fever occurs after receiving H1N1 flu vaccine, how to deal with it? Can we take antipyretic? Professor Zhou Xin, director of the Department of Respiratory Medicine at the First People's Hospital Affiliated to Shanghai Jiaotong University pointed out that generally patients would have low fever after receiving H1N1 flu vaccine, and basically the fever would be gone within one or two days, so don't take medicine indiscriminately.