Seorang lansia Korea Selatan menerima dosis pertama vaksin virus corona Pfizer-BioNTech di pusat vaksinasi di Seoul, Korea Selatan, 1 April 2021.

South Korea, DTulis.com - Health authorities in South Korea are expanding booster shots to adults aged 50 and older after COVID-19 cases rose again across the country.

More than 40,000 new cases were reported Wednesday (13/7), marking the country's highest daily jump in more than two months, although the number of hospitalizations and deaths remained stable.

Baek Gyeongran, South Korea's leading infectious disease expert, attributed the increase in the number of cases to reduced immunity after previous vaccinations and infections, and the massive removal of social distancing rules since April when the country finally managed to contain a surge in omicron cases.

Health officials also found a "rapid spread'' of BA.5, which is seen as the most contagious variant of omicron, Baek said.

South Korea has previously given a second booster shot to people who are 60 years of age or older and those with weakened immune systems. Officials are now extending the viability of the shot to people in their 50s and all adults with pre-existing medical conditions.

A week-long quarantine will be maintained for people who test positive.

Officials say the country may face a daily case count of 200,000 by mid-August or September if infections continue to rise. However, they have no immediate plans to re-impose social distancing restrictions, which have been effectively replaced with indoor mask mandates over the past few months.

Baek, commissioner of korea's Disease Control and Prevention Agency, said the government would focus on expanding booster shots and securing a larger supply of antiviral pills to suppress hospitalizations and deaths.

He said re-enacting strict social distancing rules was a last resort, given the weak economy, but called on people to cancel unnecessary gatherings and travel.

Authorities also stepped up border controls. All newly entered the country must now undergo a PCR laboratory test on the day of arrival and undergo mandatory quarantine at home until the results come out. Those planning to visit the country must also present a negative antigen or PCR test result at least 48 hours before departure.