[COVID-19 Resurgence] What Are the Symptoms of BA.5 Before Becoming the Dominant Strain? ... More Severe Sore Throat and Nasal Congestion

24.1% by the End of June... May Exceed 50% as Early as This Week
Neutralizing Antibody Production Three Times Lower Against Omicron, Easier Reinfection
Fever, Fatigue, Cough, and Other Typical COVID-19 Symptoms Remain

The Central Disease Control Headquarters of the Korea Disease Control and Prevention Agency announced that 20,410 new COVID-19 cases were reported as of midnight on the 10th. On the same day, the screening clinic set up at Jung-gu Public Health Center in Seoul was crowded with citizens and foreigners seeking testing. Photo by Moon Honam munonam@

[Asia Economy Reporter Lee Gwan-joo] The recent surge in new COVID-19 cases reaching the 20,000 range over the past two days is largely attributed to the Omicron subvariant ‘BA.5’. It is analyzed that BA.5 has stronger transmissibility than the existing Omicron variant and better immune evasion from immunity acquired through existing vaccines or infections, making breakthrough infections easier to occur. 'COVID-19 Strikes Again'

According to the quarantine authorities on the 11th, the detection rate of the BA.5 variant among domestic infections was only 0.9% in the second week of June, but it increased to 24.1% by the fifth week, three weeks later. Especially among overseas inflow patients, nearly half, 49.2%, were infected with the BA.5 variant. It is expected that the detection rate of BA.5 will exceed 50% and become the dominant strain as early as this week or at the latest next week.

The rapid spread of BA.5 is due to its greater transmissibility compared to the existing Omicron variant. Research shows that BA.5’s transmissibility is 35.1% stronger than that of the stealth Omicron (BA.2). Also, the level of neutralizing antibody production is about 20 times lower than the original COVID-19 virus and about 3 times lower than the Omicron variant. This means that even if immunity is formed through vaccination or infection, BA.5 can easily cause infection and reinfection.

These characteristics of BA.5 have also been confirmed in the COVID-19 resurgence in the United States, Europe, and other regions. As of the 26th of last month, it is estimated that 43% of new cases worldwide were infected with BA.5. The detection rates of BA.2 and its subvariant BA.2.12.1, which previously led the outbreak, decreased from 30% to 25% and from 18% to 11%, respectively. In Europe, the number of new cases in the week ending June 26 was 1,796,850, a 33% increase compared to the previous week.

Regarding symptoms of BA.5 infection, since it is an Omicron subvariant, the consensus is that symptoms are not significantly different from before. They mainly include sore throat, fever, nasal congestion, cough, muscle pain, and fatigue. Clinical results compiled in the United States indicate that sore throat and nasal congestion symptoms may be more severe. Loss of smell and taste is less frequent than before. Considering that the fatality rate has not increased in the currently ongoing outbreaks in the United States and Europe, there is speculation that the severity and fatality rate may be similar to or lower than those of the Omicron variant. Son Young-rae, head of the Social Strategy Division at the Central Disaster and Safety Countermeasures Headquarters, recently stated in a briefing, “Although the reinfection rate has increased, the existing severity and fatality rates are likely similar or even lower. It is still difficult to categorize unique symptoms specific to BA.5 separately. Overall, COVID-19 symptoms continue to appear,” he explained.

However, since clear data on severity and fatality rates have not yet been established, high-risk groups such as the elderly and those with underlying high-risk conditions still need to exercise caution. Some studies have shown that unlike healthy young people, high-risk groups have higher hospitalization and fatality rates upon reinfection compared to the initial infection. The quarantine authorities are currently conducting monitoring through epidemiological data analysis to assess the impact on severity and fatality rates.