It might surprise you that our immune systems have a memory, and it is crucial in our battle against diseases like COVID-19. The secret of improving this memory might be living inside you already. A research team from CUHK’s Faculty of Medicine has discovered the critical role that certain gut bacteria can play in lengthening the duration of immune responses to COVID-19 vaccines. The problem is, not everyone has them. As a result, they’ve come up with a supplement containing the beneficial bacteria, and demonstrated how effective it can be in boosting immunity. Now they’re looking at what our gut microbiome can do to protect us from other diseases.