Do health regulations need paper proof to change nucleic acid?

You don't need paper proof to change the nucleic acid of health code, you just need to make a nucleic acid.

There is no requirement that all localities must hold paper-based negative nucleic acid testing certificates. The electronic version of the health code display and the paper nucleic acid negative test certificate issued by medical institutions within 48 hours can be used. At present, railway stations and high-speed railway station in many areas need to check the negative certificate of nucleic acid test within 48 hours.

The negative certification time of nucleic acid detection within 48 hours is calculated from the sampling time. Usually, the testing time will be clearly indicated in the testing report. Under normal circumstances, the nucleic acid test results will come out in about 12 hours. If it is a large-scale nucleic acid test, the results usually take 24 hours to come out.