Jung Ki-seok, a top adviser to the government's COVID-19 task force, said on Monday that the government was concerned about the low Covid-19 booster vaccination rate during the winter season ahead of the full-fledged Covid-19 recurrence.

"Summer and winter are different as winter poses extra risks of respiratory infectious diseases such as RS viruses and flu which were not prevalent in summer,” he said. "This winter, if an individual's immunity is relatively low, there is a higher risk of becoming seriously infected.”

Currently, the flu vaccination rate for those aged 65 or older stands at 77 percent, but the winter Covid-19 booster vaccination rate for those aged 60 or older is only 12.7 percent. This is roughly half of the U.S. 26 percent vaccination rate for the same age group.

Showcasing the passiveness of vaccinations this winter, he highlighted the domestic situation.

“Our Covid-19 second vaccination rate is high at 87.1 percent of the total population as of last week Wednesday and is even higher at 96.6 percent for those 18 and over," Jung said. 

However, the third and fourth vaccination rates dropped significantly to 65.6 percent and 14.7 percent of the population respectively, he said.

Referencing the U.S, he explained, "Unlike the U.S., most of Korea's 60s and older population have been vaccinated so high-risk groups in the U.S. voluntarily decided to receive the BA.4/5 vaccine in preparation for winter, so now the U.S vaccination rates are higher than ours,”

Covid-19 is a much scarier infectious disease than the flu, transmitting to more than 15 people per person compared to less than three people per person in the case of flu, Jung noted.

Furthermore, Korea’s average annual flu death toll from 2010 to 2019 is 210 while the death toll of Covid-19 is estimated to be close to 27,000 this year.

He attributed the decline in vaccination rates to those who believe Covid-19 can be managed like the flu. "Omicron's morbidity is never the same as the flu. If they were the same, the fatality rate will drop from 0.03 percent to less than 0.01 percent, but the fatality rate of Omicron BA.5 is actually 0.06 percent.”

He stressed that the additional vaccination rate in winter for high-risk groups should be more than 60 percent and particularly, those aged 70 or older should all receive additional vaccinations.

He added that considering two-week period when immunity is acquired after vaccination, vaccination should be done immediately this week or next week to obtain sufficient immunity in late November or early December, when a full-fledged epidemic is expected.

Addressing skepticism about the BA.4/5-based improved bivalent vaccine which did not complete clinical trials, Jung explained, "The Ministry of Food and Drug Safety (MFDS) urgently approved immunogenicity and safety based on the advisory committee's judgment that it is possible to extrapolate the results from the BA.1-based vaccine clinical results. Both BA.1 and BA.4/5 Omicron variants have almost the same material, except for a small change in the mRNA sequence."

He added that other regulatory bodies in the U.S., Canada, Japan and Europe also used the same criteria and pointed out that the flu vaccine also does not undergo clinical trials every year.