Scientists with the Food and Drug Administration said Tuesday that Moderna did not meet all the criteria necessary for the FDA to support a booster vaccine.

Per Yahoo! News, FDA scientists released new documents that show the Moderna vaccine’s booster shot created antibodies. But the difference in antibody levels before and after the booster shot wasn’t big enough to warrant a booster shot.

  • In fact, those who already had high antibody levels from the first two-dose regimen did not show signs of increased antibody levels.
  • So, in a way, the Moderna shot might be too strong already to warrant a booster shot.
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John Moore, a professor of microbiology and immunology at Weill Cornell Medical College in New York, told Yahoo! News that there are still a number of questions about the Moderna booster shot and what the FDA wants from it.

  • “There was boosting, sure. Was it enough boosting? Who knows? There’s no standard amount of boosting that is known to be needed, and nor is it clear how much boosting happened in the study,” Moore said.

Unnamed sources recently told Bloomberg that the FDA might suggest a half-dose for the coronavirus booster shot since the original doses of the vaccine were so strong.

  • The original two-dose regimen from Moderna had two 100-microgram doses. 
  • For comparison, Pfizer’s first shots had two 30-microgram doses.

A half-dose for the booster shot would likely reduce the side effects of the shot, according to Bloomberg. And it would allow Moderna to spread the booster shot more widely throughout the world.

The Food and Drug Administration and the Centers for Disease Control and Prevention approved the Pfizer booster shot at the end of September. Questions were immediately raised about what this meant for Moderna and Johnson & Johnson vaccine recipients.

Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, said on NBC News’ “Meet the Press” recently that the Moderna booster shot will come soon once the right data comes along.

  • “The actual data that we’ll get (on) that third shot for the Moderna and second shot for the J&J is literally a couple to a few weeks away,” he said. “We’re working on that right now to get the data to the FDA, so they can examine it and make a determination about the boosters for those people.”