BEIJING -- More than 1.3 billion doses of COVID-19 vaccines have been administered in China as of Sunday, as the country continues to ramp up its inoculation drive, the National Health Commission announced on Monday.

China accelerated its pace of free COVID-19 vaccinations for the whole nation in late March. It took China 25 days to climb from 100 million doses to 200 million doses, 16 days to increase from 200 million to 300 million, and just six days to move from 800 million to 900 million.

By June 19, China had administered in excess of 1 billion doses, the commission announced on June 20. By June 24, the accumulative figure exceeded 1.1 billion, and by June 28, the number surpassed 1.2 billion.

Experts with the Chinese Center for Disease Control and Prevention have called for vaccine dose schedules to be completed in full to achieve the best possible preventative effect.