SEOUL - South Korea on Friday launched its mass COVID-19 vaccination nationwide, starting with patients and health workers under the age of 65 in nursing hospitals and facilities.

The free vaccination campaign began at 9:00 a.m. local time across the country. On the first day, 5,266 patients and health workers in 213 nursing facilities are scheduled to be inoculated, according to the Korea Disease Control and Prevention Agency (KDCA).

Separately, 292 nursing hospitals started administering vaccines according to their own schemes of inoculation that is slated to be completed in five days.

The first batch of the two-dose AstraZeneca vaccines will be administered to a total of 289,480 patients and health workers in 1,657 sanatoriums and 4,147 elderly care and rehabilitation facilities who agreed to the vaccination.

It represents 93.7 percent of the total personnel and patients in the facilities. The health authorities aimed to finish administering the first jabs in the long-term care facilities in March.

The AstraZeneca vaccines were manufactured at a domestic plant of SK Bioscience, the pharmaceutical unit of South Korea's third-biggest conglomerate SK Group.

SK Bioscience signed a consignment manufacturing deal with the British-Swedish drug producer last year, and also with the US pharmaceutical company Novavax earlier this month.

From Saturday, the vaccination campaign will kick off for 54,498 medical workers treating COVID-19 patients in 143 hospitals and 35 residential treatment centers across the country. It represents 95.8 percent of the total personnel.

The medical staff will receive the two-dose vaccines of US drug maker Pfizer. The health authorities planned to complete the first shots by March 20.

South Korean President Moon Jae-in vowed to provide vaccines to all of the country's 52 million population free of charge, aiming to almost completely form a herd immunity no later than November.

In the latest tally, the country reported 406 more cases of COVID-19 for the past 24 hours, raising the total number of infections to 88,922.