"Janssen Vaccination 5 Months Later Preventive Effect 3%... US Experts Urge Fastest Possible Booster Shot"

[Image source=Yonhap News]

[Asia Economy Reporter Seoyoung Kwon] Experts in the United States are reportedly urging booster shots for the COVID-19 Janssen vaccine (a subsidiary of Johnson & Johnson).

On the 16th (local time), CNN and the New York Post reported that these calls came after new research showed that the efficacy of the Janssen vaccine significantly declined during the spread of the Delta variant. A booster shot refers to an additional vaccination administered beyond the originally established completion criteria to restore the waning effectiveness of the vaccine over time.

The Vaccine and Related Biological Products Advisory Committee (VRBPAC), an advisory body to the U.S. Food and Drug Administration (FDA), unanimously recommended approval of the Janssen booster shot the day before. The FDA advisory committee advised that those who received the single-dose Janssen vaccine should get a Janssen booster shot two months after the initial vaccination. CNN then cited data from the U.S. Centers for Disease Control and Prevention (CDC), reporting that 91% of the 15 million people vaccinated with the Janssen vaccine in the U.S. completed their vaccination about two months ago.

On the afternoon of September 8, an undocumented Chinese resident living in the nearby area received the Janssen COVID-19 vaccine at the Yeongdeungpo Health Center branch in Daerim-dong, Yeongdeungpo-gu, Seoul.
[Photo by Yonhap News]

The New York Post stated that this decision was made due to concerns that the Janssen vaccine might be less effective than the vaccines developed by Pfizer-BioNTech and Moderna. On the 14th, a study showed that the COVID-19 prevention effectiveness among 620,000 veterans vaccinated with the Janssen vaccine was 88% in March this year but dropped to 3% five months later in August. This decline is much steeper compared to Pfizer and Moderna, whose prevention effectiveness decreased from 91% to 50% and 92% to 64%, respectively, over the same period.

In response, Dr. Paul Offit, an FDA advisory committee member, stated, "For those who have received the Janssen vaccine once, a second Janssen vaccination could be beneficial." He also explained, "If it were not for the urgent situation caused by the pandemic, the Janssen vaccine would have been completed with two doses."