It's free. According to the latest statement of epidemic prevention and control in Nanjing, by the end of June, 2022, 65438+1October, 65438+1October, Nanjing University had implemented the policy of exemption for middle school students. Nanjing University actively cooperated with the measures taken by the Center for Epidemic Prevention and Control, conducted daily nucleic acid tests on students who were not isolated in the school, implemented prevention and control measures, and did not gather outdoors to wear masks.