The Janssen Vaccine, Effective with Just One Dose, Is Coming

Passed 1st Review by MFDS
Effectiveness Recognized Based on Multinational Phase 3 Trials

66.9% Prevention Rate 14 Days After Administration
Immune Response Maintained Up to 12 Weeks... Additional Period Under Monitoring

Official Approval Decision Expected Early Next Month

[Asia Economy Reporter Lee Chun-hee] The Janssen (a subsidiary of Johnson & Johnson) COVID-19 vaccine, which shows preventive effects with just one dose, has passed the first verification by the Ministry of Food and Drug Safety (MFDS).

On the 29th, the MFDS announced that at the verification advisory committee meeting held the previous day, after discussing clinical trial data of the Janssen vaccine, it was judged that the preventive effect required for the approval of the Janssen vaccine could be recognized.

Korea Janssen, the Korean branch of Janssen, applied for the product approval of the COVID-19 vaccine to the MFDS on the 27th of last month. It has thus passed the first hurdle for approval in just over a month.

The MFDS reviews COVID-19 vaccines and treatments through a triple advisory process involving the verification advisory committee, the Central Pharmaceutical Affairs Deliberation Committee, and the final inspection committee before granting approval. Six experts, including infectious disease specialists, vaccine experts, and clinical statistics experts, attended this advisory committee meeting.

The Janssen vaccine is a “viral vector vaccine” manufactured by inserting the gene of the COVID-19 virus surface antigen into an adenovirus template. It is the only COVID-19 vaccine scheduled for domestic introduction that was developed with a single-dose regimen. Six million doses are expected to be introduced in the second quarter. However, the specific introduction schedule has not yet been finalized.

66.9% prevention rate after 14 days, 66.1% after 28 days... Antibody levels maintained up to 12 weeks

Kim Sang-bong, Director of the Bio-Pharmaceutical Division at the Ministry of Food and Drug Safety, is announcing the results of the Janssen (Johnson & Johnson) COVID-19 vaccine review advisory committee meeting on the morning of the 29th at the briefing room of the Ministry of Food and Drug Safety in Cheongju, Chungbuk.
[Image source=Yonhap News]

The verification advisory committee evaluated the Janssen vaccine based on a total of four clinical trial data sets submitted by Korea Janssen. Among these, a multinational phase 3 clinical trial conducted in the United States, Argentina, Brazil, South Africa, Peru, Chile, Colombia, and Mexico formed the basis for safety and efficacy evaluation. The clinical trial involved a total of 43,783 participants, including 17,858 (40.8%) with underlying diseases and 8,561 (19.6%) elderly participants aged 65 or older.

According to the clinical trial results, 116 out of 19,630 vaccinated individuals were confirmed COVID-19 positive 14 days after vaccination, compared to 348 out of 16,915 in the control group, showing a prevention rate of 66.9%. Additionally, a 66.1% preventive effect was observed 28 days after vaccination. The prevention rate after 14 days was over 66% regardless of age or presence of underlying diseases. The advisory committee also analyzed that the vaccine showed a 76.7% prevention effect against severe COVID-19 after 14 days and 85.4% after 28 days.

The Janssen vaccine also demonstrated effectiveness in immunogenicity assessments, an indirect measure of vaccine efficacy. The seroconversion rate, which is the proportion of subjects whose antibody titers increased more than fourfold compared to before vaccination for binding antibodies that attach to the COVID-19 virus antigen, reached 95%. The seroconversion rate for neutralizing antibodies, which neutralize the virus’s infectivity and induce preventive effects, was also above 90%.

Based on this, the advisory committee judged that "the effect has been confirmed, and the immune response is maintained up to 12 weeks, so the preventive effect required for approval can be recognized." Park In-sook, head of the MFDS Biologics Review Division, added, "This currently means that antibody levels have been maintained up to 12 weeks," and noted that long-term sustained effects are being monitored.

On the 11th, the United States Forces Korea Command announced that it had started administering the Janssen COVID-19 vaccine. The photo shows Lieutenant Colonel Juliet Morarives, an emergency treatment nurse and the first person to receive the Janssen vaccine at all US military bases in Korea, getting vaccinated at Brian Allgood Hospital within Camp Humphreys, posted on the hospital's Facebook account. [Image source=Brian Allgood Hospital Facebook] [Image source=Yonhap News] Photo by Yonhap News

The verification advisory committee also judged the safety of the Janssen vaccine to be at an acceptable level. Most local and systemic reactions after vaccination disappeared within three days, and the incidence and severity in the elderly were lower compared to adults.

However, during the clinical process, seven cases of ‘serious adverse drug reactions’ that could not exclude a relationship with vaccination were reported. These included one case each of Guillain-Barr? syndrome, pericarditis, brachial neuritis, post-vaccination syndrome, and hypersensitivity, and two cases of facial paralysis. The MFDS explained, "Most of these cases were in recovery at the time of submission of the clinical trial data."

The MFDS plans to receive advice from the Central Pharmaceutical Affairs Deliberation Committee, the second advisory stage, on the 1st of next month and disclose the results that afternoon. Since the MFDS has announced a significant reduction in the COVID-19 vaccine approval and review period from the existing six months to within 40 days, the formal approval decision for the vaccine is expected to be made in early next month. Previously, the AstraZeneca vaccine received formal approval 37 days after the application was submitted, and the Pfizer vaccine was approved after 39 days.

This content was produced with the assistance of AI translation services.