On May 16, the Central Epidemic Command Center (CECC) announced that when confirmed cases fill in vaccination status of their live-in family members who had close contact with them on the "contact tracing self-reporting system," if they select the option "have received a COVID-19 booster dose and will practice self-initiated epidemic prevention" (checking this box means live-in family members will follow self-initiated epidemic prevention measures and not be given a home isolation notice), the self-reporting system will automatically identify such family members as persons subjected to self-initiated epidemic prevention and will not issue a home isolation notice to such family members. If family members living with confirmed cases have received a booster shot but wish to adhere to the 3+4 home isolation protocol, this option should not be selected.

With respect to whether the new home isolation policy, under which close contacts with three shots don't need to isolate at home, applies to students in junior and high schools, the CECC explained that there is no such issue because the third dose has not been available for these students yet.