Health Team

Duke study finds omicron antibodies fall six-fold in Moderna booster after six months

A Duke Health study on the Moderna booster shot reveals the shot showed signs of decreasing antibody levels against the omicron variant after six months.

Posted Updated

DURHAM, N.C. — A Duke Health study on the Moderna booster shot reveals the shot showed signs of decreasing antibody levels against the omicron variant after six months.

Co-corresponding author and researcher David Montefiori found that omicron neutralization levels rose 20-fold within four weeks after the boost was given. However, those levels fell 6.3-fold six months after.

Despite the findings, the antibodies in the dose still remained effective against the variant in laboratory tests.

The study was published in the New England Journal of Medicine on Wednesday. Researchers found that the levels of these antibodies declined faster for omicron than for the early SARS-CoV-2 virus that was circulating in 2020.

“The drop in antibodies for the booster is very similar to the drop in antibodies to the delta variant that was noted six months after the second dose of the vaccine,” Montefiori said.

“This is not uncommon for mRNA vaccines or for vaccines in general,” Montefiori said. “Antibodies go down because the body figures it does not need to maintain them at that high level. It doesn’t mean there is no protection -- there is immunologic memory.”

Moderna is looking into a new vaccine formula to target omicron. That version was not used in the booster study.

Montefiori said he's concerned that the virus might change enough to prompt a modification in the vaccine and a fourth shot may be needed.

“Our data show we are not there yet,” Montefiori said. “The vaccines are still working, and the boost is helping it to work better, even against omicron.”

Dr. Anthony Fauci sounded cautiously optimistic Sunday that the omicron wave was peaking nationally in the United States and that coronavirus cases could fall to manageable levels in the coming months.

 Credits 

Copyright 2024 by Capitol Broadcasting Company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.