Immune Decline Due to Variant Influx... "100,000 to 200,000 Cases Possible This Summer"

[Unfinished COVID-19] Warning of Resurgence Due to New Variant Influx
Autumn Major Outbreak May Arrive Earlier, Peak Possible in September-October

As the COVID-19 pandemic subsides and demand for overseas travel increases, the threat of the influx of COVID-19 variants and monkeypox is gradually rising. On the 26th, at the departure hall of Terminal 1 of Incheon International Airport, an airline staff member wearing protective clothing is guiding passengers heading to China. Photo by Moon Honam munonam@

Warnings are mounting that COVID-19 will see a resurgence in South Korea due to the influx of new variants and waning vaccine effectiveness leading to decreased immunity. Although the number of new confirmed cases is gradually declining, it is expected to plateau for a while and then possibly increase again as early as this summer.

According to health authorities on the 30th, nine private research teams currently predicting the domestic COVID-19 trend, including the Korea Disease Control and Prevention Agency (KDCA), have accepted a COVID-19 resurgence in the second half of this year as a given. On the 25th, Park Hyang, head of the Central Disaster and Safety Countermeasure Headquarters' quarantine team at the Ministry of Health and Welfare, stated at a briefing, "A resurgence may appear as early as summer, with confirmed cases potentially reaching 100,000 to 200,000." Earlier, Kim Heon-ju, first deputy head of the Central Disease Control Headquarters at KDCA, also said, "Depending on the waning immunity effect, the resurgence could start as early as this summer and peak around September to October."

COVID-19 is generally known to subside during the summer, but it is not yet confirmed whether variant viruses will follow this pattern. Moreover, most quarantine measures, except for confirmed case isolation and indoor mask-wearing mandates, have been lifted, overseas travel has resumed, and citizens' outings and mobility have returned to pre-COVID-19 levels. Increased air conditioner use during summer without regular indoor ventilation could further raise infection risks.

Professor Jung Jae-hoon of the Department of Preventive Medicine at Gachon University College of Medicine said, "There are several scenarios, but a new variant may be discovered around summer to early fall, with the epidemic spreading and confirmed cases slightly increasing around September to October." He added, "The new variant may have higher transmissibility than Omicron and may not have a reduced severity rate." Professor Kim Woo-joo of the Infectious Diseases Department at Korea University Guro Hospital warned, "Factors such as the spread of new variants, decreased immunity, relaxed quarantine measures, and low vaccination rates will collectively influence the summer resurgence."

Omicron sublineage variants imported from the United States and South Africa have also been detected domestically. These countries have already begun experiencing a resurgence. According to reports from the Washington Post (WP) and others on the 29th (local time), the United States is currently seeing over 100,000 daily COVID-19 cases?about five times higher than the previous year?leading up to Memorial Day (May 30).

In the U.S., the Omicron subvariant BA.2.12.1 has become dominant and is spreading rapidly. According to estimates from the U.S. Centers for Disease Control and Prevention (CDC), between May 15 and 21, 58% of new daily cases were infected with BA.2.12.1. WP reported, "U.S. health authorities are preparing for a rapid spread of COVID-19 starting from Memorial Day, anticipating a surge in cases this summer."

Omicron variants BA.4 and BA.5, first identified last month in South Africa, are spreading from South Africa to India, the Philippines, and other countries. In mid-May, health authorities in the UK and Europe reclassified these variants from variants of interest to variants of concern and are proactively reviewing associated risks.

Immunity acquired through vaccination or COVID-19 infection wanes over time. Most people who received their third vaccine dose did so between December last year and January this year, meaning more than four months have already passed, which is concerning. Natural immunity from infections during the Omicron surge between early this year and March is also expected to decline by June or July.

However, some experts remain optimistic that only slight fluctuations in confirmed cases will occur and that a summer resurgence significant enough to be called a resurgence may not happen. Even if a resurgence occurs in the fall, it is expected not to exceed the scale of the Omicron surge.

Professor Baek Soon-young, emeritus professor at the Catholic University College of Medicine, predicted, "Since about 18 million Koreans have been infected with COVID-19 at least once, confirmed cases may rise again to around 30,000, but it may not reach a level that can be called a resurgence."

This content was produced with the assistance of AI translation services.