Sinovac and BioNTech work more effectively in people who have an abundance amount of a particular bacterium called Bifidobacterium adolescentis in their gut. In most of us, this reduces with age, modern diet, stress, and the use of antibiotics, and a joint CUHK-HKU study has found that those who lack it have a lower antibody response to the vaccines. This implies that modulating the gut has potential to power up the impact of COVID vaccines.

A university research team has found that lower levels of “good” bacteria and higher levels of “bad” bacteria in the gut of people with COVID-19 has made it harder for them to fight off the virus. The team has since developed a probiotic supplement based on this research to enhance the “good” bacteria thereby offering hope to boosting immunity against the virus in everyone who could be at risk.