Antibiotics Hinder Flu Vaccine Effectiveness

Antibiotics may cut the effectiveness of the flu shot. That’s the surprising conclusion of new studies involving mice treated with antibiotics to remove most of their gut bacteria or raised under sterile conditions.

Emory University researchers found the mice had impaired responses to seasonal influenza shots, suggesting antibiotics should be avoided before or during vaccination.

The research, to be published in Immunity by Bali Pulendran, is the latest to indicate gut bacteria affect the body’s immune system and may be a factor in the ability to fight off diseases and infections.

“Our results suggest that the gut microbiome may be exerting a powerful effect on immunity to vaccination in humans, even immunity induced by a vaccine that is given at a distant site,” said Pulendran, a professor of pathology and laboratory medicine at Emory University School of Medicine and Yerkes National Primate Research Center.