As Korea is seeing a slow increase in daily new Covid-19 cases, quarantine authorities have expressed concerns about the rise in severity and fatality rate from the virus.

"On Friday, the number of new Covid-19 infections was around 35,000, and the R0, or an estimated reproductive rate of how many people may contract the virus from one infected person, recorded 1.09, above 1 for the second week in a row," Health and Welfare Minister Cho Kyoo-hong said during a Covid-19 task force meeting Friday. "The aggravation rate and the fatality rate are also rising, with the aggravation rate rising from 0.12 to 0.19 percent and the fatality rate from 0.06 to 0.09 percent in the past five weeks."

On Friday, Korea added 35,924 new Covid-19 infections, including 60 cases from abroad, bringing the total caseload to 25,466,992, according to the KDCA.

The nation also reported 31 more Covid-19 deaths, raising the death toll to 29,100. The fatality rate stood at 0.11 percent. The number of critically ill patients came to 252, up 10 from the previous day.

Quarantine officials have attributed the increase in the severity and fatality rate to the recent increase in the proportion of infected people over the age of 60.

Among the confirmed patients on Friday, 26.3 percent were over the age of 60.

Health officials also said that the decrease in the number of tests is also having an effect on the rise in severe cases and fatalities.

"With the increase in vaccination rate, the number of Covid-19 tests has been decreasing recently," said Park Hyang, head of virus control at the Ministry of Health and Welfare's Central Disaster Management Headquarters. "We believe that the decrease in the denominator (the number of tests performed) also had a certain effect on the rise in severe cases and fatalities."

As a result, the quarantine authorities are asking the high-risk group to participate in the winter vaccination using the improved vaccine.

The government recently expanded the vaccination target to all adults over 18 from Thursday. Vaccinations are recommended for those who are hospitalized in nursing homes and facilities, workers over 50 years of age, those with underlying diseases, and those with weakened immunity.

A total of 104,337 people made reservations on Thursday, the first day of advance reservations.

A health expert also stressed the need for booster vaccination.

"The improved vaccine produces 1.5 to six times more antibodies to Omicron subvariant BA.4,5 than the existing vaccine," Professor Lee Jae-gap, an infectious disease expert at the Hallym University Gangnam Sacred Heart Hospital, said in an interview with TBS radio. "It's best to receive the vaccine."

Elderly people should be vaccinated to greatly reduce the chance of becoming seriously ill if they get infected with Covid-19 during the winter epidemic, Lee added.

According to the KDCA, about 44.68 million among 52 million Koreans have been fully vaccinated. In addition, about 33.64 million people had received their first booster shots, and 7.53 million had their second booster shots.