Janssen, Moderna Booster Shot... Reservations Start Today at 8 AM (Comprehensive)

mRNA Vaccine Recommended as Basic Option... Pfizer and Janssen Also Available Upon Request
"Studies Show Moderna 76x, Pfizer 35x, Janssen 4x Efficacy"
However, Moderna Dose Halved for Vaccination, Possibly Reducing Efficacy Slightly

Janssen COVID-19 Vaccine [Image source=Reuters Yonhap News]

[Asia Economy Reporter Lee Chun-hee] Booster shots for 1.48 million Janssen vaccine recipients will begin next month. Considering that the recommended interval for the Janssen booster shot is 2 months, the authorities will start accepting advance reservations from the evening of the 28th.

Jung Eun-kyung, head of the COVID-19 Vaccination Response Promotion Team (Director of the Korea Disease Control and Prevention Agency), stated at the regular COVID-19 briefing on the afternoon of the 28th, "For Janssen vaccine recipients, additional vaccinations will be administered 2 months after completing the primary vaccination series for all basic vaccine recipients." Advance reservations will start at 8 p.m. on the same day, and actual vaccinations will begin on the 8th of next month.

Although the previously set interval for COVID-19 vaccine booster shots by health authorities is 6 months, Janssen recipients are exceptionally recommended to receive booster shots starting 2 months after the initial vaccination. The promotion team explained, "This is due to the high rate of breakthrough infections."

The vaccines for the booster shots will basically be Moderna messenger RNA (mRNA) vaccines administered at designated medical institutions. The promotion team stated, "For Janssen vaccine additional vaccinations, the advance reservation vaccine will be Moderna."

However, depending on the medical institution's supply conditions, if recipients prefer the Pfizer vaccine, they can switch to Pfizer on-site for the booster shot. Additionally, for recipients aged 30 and above who wish to do so, it is possible to receive a Janssen booster shot by contacting the public health center.

Starting from the 1st of next month, leftover vaccine doses will be available for vaccination using the medical institution's standby list. Booster shots through same-day rapid reservations using portal applications such as Kakao and Naver are expected to be possible around mid-next month.

Moderna, Janssen, Pfizer COVID-19 vaccines (from left) [Image source=Reuters Yonhap News]

Regarding the effectiveness of booster shots by vaccine type such as Pfizer, Moderna, and Janssen, Director Jung explained based on research conducted in the United States, "When Moderna is administered as a booster, neutralizing antibody levels increase about 76-fold, Pfizer about 35-fold, and Janssen about 4-fold," adding, "Since the neutralizing ability is somewhat higher than Janssen, we recommend using mRNA vaccines as the primary booster."

However, when receiving Moderna, the dose administered will be 0.25 mL (antigen amount 50 μg), not the original 0.5 mL (antigen amount 100 μg). Director Jung said, "This is based on the U.S. Food and Drug Administration (FDA) reviewing the clinical trial results presented by Moderna and changing the approval standards regarding safety and efficacy," and explained, "Although Moderna's antigen amount is 100 μg, which is the same dose as Pfizer's 30 μg, differences in antigen amounts can affect vaccine efficacy and side effects. We analyzed clinical trial results on booster doses to establish implementation standards." He added, "If there is a direct correlation between dose and antibody formation, it can be estimated that about 50 μg of Moderna antigen would result in efficacy between 35 to 76 times, but the actual efficacy might differ somewhat from previous research results."

Regarding potential confusion caused by this change in dosage at the frontline, Director Jung said, "We will coordinate with the medical community to distinguish doses by color-coded stickers or include 'half dose' in measures to prevent misadministration, and provide guidance, education, and management to avoid any errors."

Even if some Janssen recipients refuse the booster shot for various reasons, they will not be excluded from the vaccination certificate and negative test verification system starting next month. Director Jung stated, "Currently, there is no standard that requires additional vaccination to be recognized as a vaccination certificate holder," but added, "There have been about 3,800 confirmed breakthrough infection cases, accounting for about 0.2%, so we strongly recommend receiving the booster shot whenever possible."

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