Scientists at King Abdullah University of Science and Technology (KAUST) have discovered that corals can be trained to better resist disease before an outbreak occurs, a finding that could one day help protect reefs around the world. The study, published in ISME Host Microbe, showed that corals exposed to sub-lethal doses or inactive forms of a disease-causing pathogen became more resistant when they encountered the disease again later. The process, known as pathogen priming, is similar in concept to how vaccines prepare the body to recognize future threats. The discovery is the first evidence that corals can develop a protective, immune memory-like response despite lacking the adaptive immune systems found in humans and other vertebrates. "Coral disease is becoming an increasingly important challenge for reefs worldwide," said Professor of Marine Science at KAUST and senior author of the study Raquel Peixoto. "What surprised us was finding that corals exposed to a pathogen were significantly better able to respond when they encountered the same disease agent again. It suggests corals can be trained to strengthen their natural defenses, something that was not previously demonstrated." The research also revealed that the protective effect is linked not only to changes within the coral itself, but also to changes in its microbiome, the community of microorganisms that live alongside and support coral health, SPA reported. The findings come at a time when coral reefs face growing pressure from warming oceans and other environmental stressors. Disease outbreaks can spread rapidly through reefs and coral nurseries, causing significant losses and undermining restoration efforts. Conducted using corals from the Red Sea, the research could have implications far beyond the region. The team has filed a patent application related to the use of pathogen priming to strengthen coral disease resistance and is now working to test the approach across additional coral species, pathogens, and environmental conditions. If successful, the technique could eventually provide coral nurseries and restoration programs with a new tool to help protect reefs before disease outbreaks occur.
