Paxlovid, the COVID-19 antiviral pills developed by Pfizer, have been purchased by South Korea in an additional 400,000 courses, according to health officials on Wednesday evening. With this latest purchase, the country has secured enough oral treatments for a total of 1 million people — 762,000 people from Pfizer and the remaining 400,000 from Merck — in total.

As stated in a press release issued Thursday, "the addition of pills to our treatment protocol will assist in stabilizing and expanding the at-home COVID-19 care scheme, which is a critical pillar of our return to normal."

When are they expected to arrive?

The first shipments of Paxlovid are expected to arrive in mid-January, according to the agency, although specifics such as the number of courses are still being worked out.

Who has the authority to take them?

Paxlovid is approved for use in Korea for patients 12 years of age and older who weigh at least 40 kilograms, according to the FDA.

The pills must be taken within a few days of the onset of the symptoms in order to be effective. Patients who are already severely ill and in need of hospitalization will be unable to accept them.

Although treatment guidelines are still being developed, the agency stated that pills will be prescribed primarily to COVID-19 patients in home recovery who are at a higher risk of developing severe disease.

Dr. Kim Woo-joo, an infectious disease specialist at Korea University Medical Center, is concerned that the scope of use of Paxlovid, also known as ritonavir-boosted nirmatrelvir, will be limited due to a long list of other medications that cannot or should not be mixed with it, according to him.

"According to the manufacturer, paxlovid is contraindicated in patients with severe kidney or lung disease," he explained.

Paxlovid and certain medications used to treat cancer, allergies, bacterial infections, migraines, high blood pressure, depression, and anxiety are among those that should not be taken together. Patients who are taking oral contraceptives, hepatitis C antivirals, or smoking cessation medications, among other products, are advised to inform their doctors of their use.

"As Paxlovid is made available to a larger number of people, safety monitoring will be critical, just as it has been with vaccines," Kim explained.

Most likely effective against the bacterium omicron

Later-stage trials, according to the agency, have shown that Paxlovid reduces hospitalizations or deaths by nearly 90 percent. Although it is likely that Paxlovid is still effective against omicron, according to Pfizer, there has been no official announcement regarding Paxlovid's effectiveness against omicron, and the studies are still in the early stages.

Dr. Paik Soon-young, a former member of the Central Pharmaceutical Affairs Council under the Ministry of Food and Drug Safety, said that, unlike monoclonal antibodies, the way the pills work is unlikely to be affected by viral mutations. "Unlike monoclonal antibodies, the way the pills work is not likely to be affected by viral mutations," he added.

With any other medication, your chances are slim. molnupiravir

Merck submitted an application to Korean regulatory authorities in mid-November for emergency use approval of its molnupiravir medication, which is marketed under the brand name Lagevrio. However, the application is still undergoing review. Paxlovid, manufactured by Pfizer, was approved for emergency use in the United States on December 27, just five days after the company submitted its application.

It was announced on Thursday by the disease control agency that the Drug Ministry has not yet decided whether or not to issue an emergency authorization in the case of molnupiravir.

In Korea, according to Kim Jeong-ki, a Pharmaceutical Society of Korea expert in pharmaceutical microbiology, molnupiravir has only a slim chance of being approved by the Korean regulatory authorities.

Several countries, including France, have canceled their orders for Merck's treatment after trial results revealed that it was only about 30 percent effective in reducing hospitalizations and deaths in high-risk individuals. As a result of safety concerns, including the possibility that the pill could cause mutations in human DNA, which could theoretically harm sperm cells or an unborn child, India has also abandoned the pill.

Even if molnupiravir is approved for use in Korea, according to Kim, it is unlikely to gain widespread acceptance due to safety concerns.

In other words, only about 700,000 courses of Pfizer pills would be left over for Korea to consume. "At the current rate of growth, the amount we have appears to be sufficient, but it is also contingent on how omicron will play out," he explained.