BA.5 with the Fastest Transmission Speed... Is the Answer the 4th Vaccination?

Faster Spread... Confirmed Cases 'Doubling' and Reproduction Number at 1.40
Infection Control Difficult Due to 'Relaxed' Quarantine Policies
Government Finally Expands 4th Vaccination Eligibility

On the 12th, with 37,360 new COVID-19 cases reported, marking the first time in 55 days that the number has fallen into the 30,000 range, citizens lined up to get tested at a screening clinic set up at Mapo-gu Public Health Center in Seoul. Photo by Jinhyung Kang aymsdream@

[Asia Economy Reporter Yoon Seul-gi] The sixth wave of COVID-19 is gaining momentum as the spread of BA.5 (Bi-Ai-Pa-I-beu), known as the fastest-spreading variant among all COVID-19 variants to date, accelerates. However, considering the difficulty of implementing strict quarantine policies amid the established atmosphere of daily life recovery, the government has decided to expand the fourth vaccination campaign.

According to the Central Disease Control Headquarters (CDCH) on the 12th, 37,360 new COVID-19 cases were reported that day. The 'doubling' phenomenon, where the number of confirmed cases doubles compared to the previous week, has continued for nine days, indicating a faster spread. The effective reproduction number also rose to 1.40, marking five consecutive weeks of increase. The effective reproduction number quantifies how many people one infected person transmits the virus to; a value above 1 indicates epidemic expansion, while below 1 indicates containment.

As the doubling phenomenon continues, analyses suggest that this wave resembles the Omicron variant outbreak. During the Omicron wave in late January to early February, the number of confirmed cases doubled faster than government predictions, and in March, when the Omicron variant detection rate reached 100%, daily new cases hit record highs. The Omicron variant peaked in mid-March with over 600,000 new cases per day before entering a decline phase.

However, recently, the BA.5 variant, which spreads 35.1% faster than BA.2 (Stealth Omicron) and has the characteristic of evading vaccine-induced immunity, is showing signs of becoming the dominant strain, causing a resurgence of COVID-19.

According to the CDCH, in the first week of July, the BA.5 detection rate was 35.0% (23.7% domestic, 70.0% imported), up 6.8 percentage points from the previous week (28.2%). The increase in BA.5 detection rate is attributed to a rise in imported cases. Of the total 260 BA.5 variant cases, 120 were domestic infections and 140 were imported. While the domestic detection rate slightly decreased from 24.1% the previous week, the imported case detection rate surged from 49.2% to 70.0%.

Especially in the metropolitan area and Jeju, where imported cases are high, the BA.5 detection rate is elevated. Considering the high transmissibility of BA.5 and the summer vacation season, there are concerns that it could spread to non-metropolitan regions.

On the 27th of last month, nurse Lee Hanna, who will be treating monkeypox patients, is receiving the monkeypox vaccine at the main building of the National Medical Center in Jung-gu, Seoul. Photo by Moon Honam munonam@

◆ The Realized '6th Wave', Difficult to Tighten Quarantine Policies... Is the 4th Vaccination an Alternative?

Previously, under the Moon Jae-in administration, strong quarantine measures such as mandatory indoor and outdoor mask-wearing, restrictions on business hours, and limits on the number of people were implemented to curb the spread. However, as social distancing has relaxed and become part of daily life following the lifting of outdoor mask mandates, it is difficult to enforce previous high-intensity quarantine policies. Strong policy enforcement is expected to face public resistance; during the previous government's business hour restrictions, self-employed individuals dissatisfied with the measures staged large-scale protests.

The reduction in the number of COVID-19 screening clinics is also problematic. During the large-scale COVID-19 outbreak, screening clinics were increased to proactively block infection sources, but as the number of diagnostic tests and confirmed cases sharply declined, many clinics closed.

With no suitable alternatives to control the sixth wave, the government has introduced the fourth vaccination recommendation. On the 13th, Prime Minister Han Duck-soo stated at the Central Disaster and Safety Countermeasure Headquarters (CDSCH) meeting at the Government Seoul Office, "We will expand the target groups for the fourth vaccination," announcing that the fourth dose eligibility will be extended from the existing '60 years and older' and 'immunocompromised' groups to include people in their 50s and 'those aged 18 and older with underlying conditions.'

Prime Minister Han said, "The BA.5 variant, which spreads rapidly and has immune evasion characteristics, is spreading in Korea, causing the resurgence to start faster than initially expected," adding, "The Korea Disease Control and Prevention Agency and experts predict that daily confirmed cases could reach up to 200,000 between mid-August and late September."

He continued, "The fourth vaccination can prevent progression to severe COVID-19," emphasizing, "The government strongly recommends vaccination for the target population." He also stated that vaccination will be expanded not only to nursing hospitals and facilities but also to facilities for the disabled and homeless shelters among vulnerable facilities.

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