The government is moving to administer a second COVID-19 booster shot for nursing home residents to help prevent cluster and breakthrough infections amid the rapid spread of the omicron variant. 

The Korea Disease Control and Prevention Agency(KDCA) said on Monday that the fourth vaccination plan is currently being set up for those staying or working at nursing homes and other facilities vulnerable to COVID-19 infections. 

The vaccine developed by U.S. pharmaceutical company Novavax will be used for the new inoculation program, particularly for those who have to be vaccinated, it said. 

According to the agency, January saw the outbreak of 66 cluster infections at nursing homes across the nation that produced a total of two-thousand-490 new COVID-19 cases. In the first week of February alone, 121 new cases from seven cluster infections were reported. 

Authorities suspect the number of COVID-19 infections among those aged 60 and older will further increase in March and onward as the efficacy of the first booster shot wears off. 

Meanwhile, over 92 percent of coronavirus cases detected in the nation last week involved omicron, up from 80 percent a week earlier. The virus reproduction rate, or the number of infections caused by a single patient, also rose from one-point-58 to one-point-six in the same period.