New Vaccine Could Fight Hospital-Acquired Infections by Boosting the Immune System

A new type of vaccine could stimulate the innate immune system to prevent deaths from hospital-acquired infections (HAIs) caused by a variety of bacteria and fungi, according to a recent study. While traditional vaccines teach the body’s adaptive immune system to recognize and remember a protein from a single type of microbe, this alternative approach stimulates the innate immune system.

The study, which tested protein-free vaccines on mice, found that the innate immune cells “keep a kind of memory, lasting weeks to months, that allows them to react more effectively the second time they encounter a pathogen.” In mice, the vaccine protected against death from a bloodstream infection of methicillin-resistant Staphylococcus aureus, but did not protect against death from pneumonia. In an additional test, the vaccine protected mice from several different microbes delivered to the bloodstream or the lungs. Protection was provided within 24 hours and up to 28 days, and after a booster shot, protection continued for several weeks.