The accumulated Covid-19 caseload in Korea neared 20 million on Tuesday, meaning that almost two of five Koreans have tested positive for the virus.

The country reported 111,789 more new virus cases on Tuesday, raising the total caseload to 19,932,439, according to the Korea Disease Control and Prevention Agency (KDCA).

The daily caseload marks the highest since April 19, when the comparable figure was 118,474.

Imported cases also marked a record high of 568 since Korea reported its first Covid-19 case in January 2020. The number of imported cases has been in triple digits since June 24, after the government eased entry restrictions, such as quarantine exemption for inbound travelers.

Notably, quarantine officials stressed that with the recent summer vacation season, the number of travelers arriving in Korea had risen sharply. The death toll came to 25,084, up 16 from the previous day, with a fatality rate of 0.13 percent. The number of critically ill patients decreased from 287 to 282.

Authorities expected the total caseload to breach the grim milestone of 20 million during the day.

However, health experts expect that the number of people who have actually been infected would be much higher when, considering hidden infections, asymptomatic patients and those who did not receive a test despite having symptoms.

Experts estimate that if the government includes hidden infections, the actual number of infected people will be twice that of the official report, which means that the number of infected people may be around 40 million.

The BA.5, an Omicron subvariant far more contagious and immunity-avoiding than earlier strains, has also officially become the dominant strain in Korea.

According to the authorities, the local detection rate of BA.5 in the fourth week of July was 60.9 percent, up 11.8 percentage points from the previous week's 49.1 percent.

Health officials consider a certain strain dominant in Korea if the local detection rate exceeds 50 percent.

When added to the high detection rate of 79.4 percent among foreign inflows, the overall detection rate of BA.5 surged to 66.8 percent.

However, health officials do not seem to be concerned about BA.5 becoming a dominant strain in Korea.

"Although BA.5 has a high infection rate and a tendency to avoid immunity, we have yet to confirm that it increases the severity in patients," the Central Disease Control Headquarters said. "Clinical symptoms are also considered to be similar to Omicron as it is a subvariant."

The country also confirmed two additional BA.2.75 cases on Tuesday, increasing the total caseload of the subvariant to nine.

According to the authorities, the latest patients arrived from India and have already been released from quarantine.

BA.2.75, or Centaurus, was first sequenced in India in May and has been found in about 10 countries, including the U.S., Australia, and Germany. According to health officials, BA.2.75 has many mutations in the spike protein compared to previous subvariants, making the virus bind to cells more effectively and evade antibodies formed by vaccines or infections.

Despite the continued spike in cases and the spread of the contagious Omicron subvariant, the government is still maintaining its initial decision of not considering a rollback of the antivirus restrictions, tight social distancing and business hour curfews. The government said the post-pandemic efforts toward regaining normalcy will continue.

Health authorities and local experts have also recently stressed that the current wave could peak at around 200,000 infection cases a day, lower than the previous prediction, given the weaker-than-expected spread of the subvariant.

"If the virus wave develops within the predicted range, we should be able to respond with the prepared quarantine and medical capabilities without uniform social distancing measures like limiting the number and size of private gatherings," KDCA Commissioner Peck Kyong-ran said on Friday.

According to the KDCA, about 44.65 million among 52 million Koreans have been fully vaccinated. In addition, about 33.46 million people had received their first booster shots, and 5.69 million had their second booster shots.