US National Institutes of Health: "Moderna Booster Shot Best After Janssen Vaccination... Antibodies Increase 76-Fold"

Effectiveness of Janssen Booster Shot is Only 4 Times After Janssen Vaccination
FDA Approval of Mixed Booster Shots Likely to Increase Medical Staff Discretion

[Image source=Reuters Yonhap News]

[Asia Economy Reporter Hyunwoo Lee] The U.S. Food and Drug Administration (FDA) is reviewing measures to allow booster shots using vaccines from different manufacturers than the original completed vaccination. Meanwhile, the U.S. National Institutes of Health (NIH) announced that receiving a Moderna vaccine after a Janssen vaccine can increase antibody levels by up to 76 times.

According to the New York Times (NYT) on the 18th (local time), the NIH reported research results on the efficacy of mixed booster shots using different vaccines to the FDA expert advisory committee. The study found that the most effective mixed booster shot combination for antibody formation was receiving a Moderna booster after a Janssen vaccine, with antibody levels surging up to 76 times within two weeks.

The NIH stated that antibody increases were only fourfold when Janssen recipients received a Janssen booster. When Janssen vaccine recipients received the Pfizer vaccine, although it did not match the Janssen-Moderna combination, antibody production was higher than when receiving the same vaccine again, the NIH reported.

However, the NYT pointed out limitations of this study, including that it was conducted over a short period with a small number of volunteers, and that another key indicator of vaccine efficacy, the production of immune cells, was not addressed in this research.

With these findings revealing the effectiveness of mixed booster shots for the first time, frontline medical personnel are expected to gain some discretion in mixing vaccines. Dr. Clay Marsh, West Virginia's COVID-19 response chief, told the NYT, "It is much easier for authorities to secure Moderna or Pfizer vaccines than Janssen," adding, "Vaccination officials will likely prefer mixed booster shots for convenience."

Meanwhile, the U.S. FDA is expected to allow booster shots for Janssen recipients aged 18 and older, but for Moderna and Pfizer recipients, boosters will be permitted only for those aged 65 and older or high-risk groups. To date, 15 million people in the U.S. have completed COVID-19 vaccination with the Janssen vaccine, which is fewer than those vaccinated with Moderna (69.5 million) and Pfizer (105 million) vaccines.