This photo taken Dec. 10 at a Seoul vaccination clinic shows syringes filled with Moderna booster doses. (Yonhap)

South Korea is considering whether to distribute a fourth dose of the COVID-19 vaccine to some vulnerable populations now that the booster vaccination program is well underway for people aged 18 and over.

Ministry of Health and Welfare spokesperson Son Young-rae said in a news briefing Tuesday whether to distribute fourth doses in the coming months was being discussed within the ministry and other concerned government agencies.

“Whether a fourth dose is going to be necessary at all has not yet been determined,” he said. The national immunization advisory committee is expected to soon hold a meeting to review the possibility of giving additional vaccinations beyond a third dose.

“But some patients with immunocompromised conditions may not be able to build and sustain their immunity even after a third dose,” he said.

He added that it was still too early to tell the extent to which the omicron variant is able to weaken existing vaccines and how long the protection from a booster lasts. “At the moment nothing has been decided yet with regards to a fourth dose, and we’re monitoring vaccine decisions overseas and assessing the upcoming data,” he said.

On the news that some companies like Pfizer were working on a variant-targeting vaccine, expected to become available by March, Son said that the terms of the contract that Korea has with the company state that in the event the vaccine is updated, the country is to be provided with the renewed vaccines.

So far in Korea, 93 percent of people aged 18 and above have been “fully vaccinated” with a two-dose AstraZeneca, Pfizer or Moderna series or Johnson & Johnson’s single dose, and 42 percent have been boosted with a Pfizer or a Moderna dose. Among older adults 60 and up, 94 percent have been fully vaccinated and 78 percent boosted.

The government aims to complete booster vaccinations of eligible adults over the first three months of the year. Anyone 18 and older is eligible to be boosted in Korea once three months have elapsed since the completion of a primary series.

The decision on extending vaccinations to younger children under 12 is still pending in Korea. The rollout for 12-  to 17-year-olds began in mid-October, with 75 percent given at least one dose of the Pfizer vaccine and 52 percent fully vaccinated to date. 

According to government announcements, Korea has secured 90 million doses of vaccines for this year, 80 million of which are from Pfizer and Moderna, and the rest from SK Bioscience. 

By Kim Arin (arin@heraldcorp.com)