Concerns about a resurgence of COVID-19 are again gripping South Korea, as the country has been witnessing an alarming increase in patients. The uptrend is likely to continue throughout the end of this month, health authorities here said Monday.

Just as many are taking summer breaks, the number of patients hospitalized with COVID-19 has seen a stark rise in recent weeks, with those admitted to 220 hospitals nationwide for the virus standing at 861 in the first week of August -- the highest number since early February.

The figure has sharply grown from 148 in the second week of July to 226 in the third week and 475 the following week, according to the Korea Disease Control and Prevention Agency. The latest surge is fueled by the KP.3 subvariant of the fast-spreading omicron variant, which accounted for 45.5 percent of the cases in July.

Of those hospitalized for the virus this month, 65.2 percent were 65 or older, followed by 18.1 percent aged 50-64.

The virus is also spurring the return of masks, self-test kits and other safety measures amid this resurgence.

In addition, drugmakers are reportedly facing a shortage of COVID-19 antiviral medications, such as Pfizer's Paxlovid and Merck Sharp & Dohme's Lagevrio, while pharmacies are running short of rapid antigen tests, according to reports. The KDCA said it plans to purchase more medicine to ensure an adequate supply.

The recent surge in COVID-19 cases has confused many, as measures to contain the virus were scrapped in May 2023 when the Korean government announced it was exiting from the state of COVID-19 national emergency and dropped its remaining antivirus mandates the following month. For now, the KDCA recommends self-isolation for patients for five days from the day of diagnosis, though it is no longer mandated. Before, the mandatory self-isolation period was seven days.

Shi Hye-jin, an infectious disease professor at Gachon University Gil Medical Center, noted that the spike has already left many people anxious.

"Compared to before, mandatory testing and quarantining have been eased, but the rate of spread is fast. Since it's not mandatory to self-isolate, it's hard to know who is infected or how one got infected. This has amplified uncertainty among the public," She explained.

A 27-year-old office worker in Seoul surnamed Kim said the summer COVID-19 wave has her walking on eggshells because she fears catching the virus and potentially negatively impacting her new workplace by transmitting it to her coworkers.

"I'm seeing more people putting on masks, including myself, and using hand sanitizer as protective measures at work. I'm also refraining from having nighttime gatherings and avoiding crowded areas to stay safe," she stressed.

"I'm scared that I could (already) be infected because I had no symptoms when I caught the virus two years ago," Kim said.

Na Hye-youn, 26, another office worker in Seoul, does not feel as apprehensive as in previous waves, since companies have already been through severe phases of the pandemic.

"I think it'd be all right if those infected work from home and employees wear masks indoors. I don't think my company will shift back to (mandatory) working from home, or at least for now," she said.

Amid the resurgence, experts have offered differing outlooks, with some saying the new wave of infection is less of a threat than previous waves, while others forecast widespread transmission.

Chun Eun-mi, a lung specialist at Ewha Womans University Medical Center, said she believes this resurgence will not cause disruptions because the health care system is better equipped to handle the virus.

"We have treatments now, and most of the population is immune due to previous infections or vaccinations. Those older with chronic illnesses or other medical conditions should be the ones concerned, as they are more prone to contracting the virus," she told The Korea Herald.

"Also, to stay safe, people should think about wearing masks when they are in crowded areas, such as when riding subways, and wash their hands well, which can reduce spread," she said.

While the resurgence is not happening at an alarming pace, Shin Hyun-young, a family medicine professor at Seoul St. Mary's Hospital, expressed concern that the health care system might struggle to cope with the surge in hospitalizations amid the junior doctors' absence.

"Medical professors have been reeling from fatigue for months now (since the standoff in the medical sector began in February). If this wave worsens and the severity increases, I'm unsure if the current medical system will handle the situation," Shin pointed out.