Korea's own vaccine may require a risky shot in the dark

Industry

Published: 09 Jun. 2021, 18:10 Updated: 11 Jun. 2021, 09:40

Korea's own vaccine may require a risky shot in the dark

People wait to see if they have an adverse reaction after being vaccinated at a public sports center in Jungnang District, eastern Seoul, Wednesday. [YONHAP]

Korea is striving to develop Covid-19 vaccines of its own, but the road is a long and bumpy one, one of the biggest potholes being finding humans for Phase 3 clinical trials.

Whether the results will be accepted internationally is also an issue.

According to the Ministry of Health and Welfare, five Korean companies have received approvals to undertake clinical trials for coronavirus vaccines: SK Bioscience, Cellid, GeneOne Life Science, Genexene and Eubiologics.

SK Bioscience may start Phase 3 clinical trials next month, the ministry said Monday. The SK Chemicals 68.4-percent-owned subsidiary is developing two vaccine candidates and plans to start Phase 3 clinical trials next month on the one of the two that looks more promising.

Cellid began Phase 2 clinical trials in late March. Eubiologics announced Wednesday that its Phase 1 clinical trial results were positive and that it's immediately embarking on Phase 2 trials.

Phase 3 are the last trials to test the safety and efficacy on human volunteers before sales approval is granted. Compared to the two previous steps, Phase 3 trials are typically the largest in size and the longest.

Despite the Korean government's promise to fast-track approvals, multiple indicators suggest that conducting Phase 3 trials alone will be tricky. The procedure will require injection of the vaccine or a placebo into tens of thousands of human volunteers. The Phase 3 trial for Pfizer's vaccine involved 40,000 people.

As latecomers to the global competition for Covid-19 vaccines, Korean companies will face a big obstacle finding the volunteers.

Korea has approved four Covid-19 vaccines for use—those from AstraZeneca, Pfizer, Janssen and Moderna. Around 15 percent of Korea's population has been vaccinated so far, and according to President Moon Jae-in earlier this month, that figure may reach 70 percent by the third quarter.

The five Korean companies may have to conduct Phase 3 clinical trials overseas. Even if the trials succeed in finding volunteers, the results can always be nullified if the trial data doesn't meet the standards to prove safety and efficacy.

Aware of obstacles these companies face, the Korean government in late May eased regulations, saying it will grant nods to "comparative" clinical trials: If the candidate substance can prove to produce a similar amount of antibodies as authorized vaccines, 3,000 volunteers and no placebo group may be enough.

That could save both time and money for the vaccine-developing companies.

Some experts cast doubt on whether Korean Covid-19 vaccines approved domestically with a small group of trial participants could receive international recognition.

Another issue is that Covid-19 vaccines of multinational bio firms are also results of fast-track approvals and clinical trials in their respective home countries last year when governments prioritized slowing the pandemic. Setting them as references in authorizing domestic products may be a questionable standard.

"For comparative clinical trials, there needs to be standards regarding trial methods and efficacy, like the amount of antibodies created—we lack of this at the moment," said Ma Sang-hyuk, vice president of the Korea Vaccine Society.

"It's highly uncertain whether foreign governments will be willing to purchase vaccines that were approved via comparative clinical trials for Phase 3."

If Phase 3 clinical trials produce positive results, the vaccine candidates will have to obtain use approval from the Ministry of Food and Drug Safety. This authorization also involves a three-step screening process, where medical experts give opinions on whether the vaccine should be granted a nod.

"SK Bioscience at the moment seems to be at the lead of entering Phase 3 clinical trials. But it won't be until next year that domestic vaccines will be available for injections," said a government official.

BY KIM MIN-WOOK, SONG KYOUNG-SON [song.kyoungson@joongang.co.kr]