BEIJING, June 7 (Xinhua) -- At least 70 percent of the target population in China is expected to be vaccinated against COVID-19 by the end of this year, according to an official of the National Health Commission (NHC).

Zeng Yixin, deputy head of the NHC, told Xinhua in a recent interview that the locally transmitted COVID-19 cases reported recently suggest that the epidemic prevention and control situation remains grim.

Calling on the public not to hesitate about vaccination, Zeng said joint efforts should be made to build the "Great Wall of Immunization."

Over 763 million doses of COVID-19 vaccines had been administered across China as of Saturday, NHC figures showed.