Breakthrough cases grow, and many get pneumonia

Medical workers care for Covid-19 patients at the intensive care unit of Bagae General Hospital in Pyeongtaek, Gyeonggi, a Covid-only hospital, on Tuesday. [YONHAP]

With breakthrough infections rising in Korea, more fully vaccinated people are ending up in the hospital with severe illnesses like pneumonia.

According to the latest government data, Korea logged a total of 44,285 breakthrough cases as of Nov. 14 out of an overall total of 395,460. With its vaccination campaign in full swing, the number of breakthrough cases has increased steadily from 8,898 in the month of September, 16,095 in October and 15,230 as of Nov. 14.

The intensive care units (ICUs) and the isolation ward in Seoul National University Hospital in central Seoul, one of the biggest hospitals in Korea, were already filled up as of mid-November — mostly by Covid-19 patients.

Five out of 12 patients in the isolation ward and 11 out of 18 ICU patients (from Nov. 1 to 17) were fully vaccinated people who later contracted the coronavirus — and 14 of them, or 47 percent of total Covid-19 patients, had their conditions deteriorate into pneumonia.

“The rate of breakthrough cases deteriorating into pneumonia has increased this month,” said Oh Myoung-don, a professor at the hospital’s Infectious Diseases Department who heads the Central Clinical Committee for Emerging Disease Control. “These people should be managed as ‘breakthrough pneumonia’ patients.”

There were barely any breakthrough pneumonia cases at Seoul National University Hospital in September. In October, cases climbed to eight out of 47 hospitalized Covid patients, or 17 percent of the total.

“If vulnerable individuals [such as older people] catch breakthrough pneumonia and have their conditions worsen, they will be put on a respirator and will have higher risk of dying,” Oh said. “The increase in Covid-19 fatalities this month isn't unrelated to the breakthrough pneumonia cases.”

Breakthrough pneumonia cases were also seen in Covid-19 designated hospitals.

In Hyundae General Hospital, a Covid-19 designated hospital in Namyangju, Gyeonggi, 44 percent of pneumonia patients hospitalized in ICU were breakthrough cases as of Oct. 25. This was raised to 69 percent as of Nov. 20.

The hospital's chief, Kim Boo-seop, said, “More and more people who have been vaccinated between June and August are receiving a high-flow oxygen therapy or even being put on a respirator after developing pneumonia.”

Korea’s health authorities have also warned about vaccine effectiveness declining over time — which is particularly dangerous for high-risk groups like the elderly.

“High-risk groups aged 60 or older accounted for 11 percent of total Covid-19 infections by the end of August, but they now have reached 36 percent,” said an official from KDCA.

“In particular, breakthrough infections among the elderly increased, which progressed to pneumonia,” the official said. “Another risk factor for death has been added.”

Jung Ki-suck, a professor of pulmonology at Hallym University Sacred Heart Hospital and former director of the Korea Centers for Disease Control and Prevention (KCDC), said, “Pharmaceutical companies like Pfizer said Covid-19 vaccines can prevent severe illnesses or hospitalization, but that was only relevant before the emergence of the Delta variant.

“Now, [the protection of] vaccines is being penetrated.” Jung called for a return to stricter social distancing rules and expansion of booster shots.

“More breakthrough pneumonia cases will come out next month when the weather gets colder,” Professor Oh said. “Many people in their 70s and 80s have difficulty visiting vaccination centers on their own. Instead of focusing on reducing the number of new infections, public health centers should operate more mobile vaccination clinics.”

Suh Ji-young, the next president of the Korean Society of Critical Care Medicine, said the country should “decide on priorities of admission and discharge from ICUs” and “come up with a transfer system for severely ill patients” in preparation for a surge in the number of people waiting for hospital beds.

On Tuesday, the number of Covid-19 patients in critical condition jumped by 34 from the previous day and hit a record high of 549. The number of severe cases hovered around 500 for seven days in a row.

With the figure already exceeding the 500-case threshold that the government has warned about, Son Young-rae, senior epidemiological strategist at the Central Disaster Management Headquarters, said in a briefing Tuesday that the country will “discuss and mull various measures including an emergency plan” if the current situation worsens.

The government earlier warned that an emergency evaluation will be held to review whether to halt the “With Corona” strategies and reintroduce stricter virus curbs if Korea’s Covid-19 risk is deemed “very high” based on their weekly virus risk assessment.

Korea reported 2,699 new infections on Tuesday. The country's cumulative caseload now comes to 420,950.

BY SHIN SUNG-SIK, SEO JI-EUN [seo.jieun1@joongang.co.kr]