Research from Radboud university medical center shows that the lockdowns during the COVID-19 pandemic had a significant impact on people’s immune response to microorganisms. During the lockdown, inflammation level in the body was low, but afterwards, the immune system reacted more intensely to viruses and bacteria. The results are now published in Frontiers of Immunology.
In this study, the researchers examined the effects of various health measures introduced during the pandemic, such as lockdowns and vaccinations. The study was conducted in a large cohort of people living with HIV, as well as in healthy individuals. The researchers found that inflammation biomarkers in the blood were low during the lockdown for people in both groups. However, when they exposed immune cells from the blood to microorganisms like viruses and bacteria in the lab, the immune system reacted much stronger than immune cells of individuals outside the lockdown.
Hygiene hypothesis
As a possible explanation for this strong immune reaction, Professor Mihai Netea from Radboud university medical center points to the hygiene hypothesis. This hypothesis suggests that regular contact with microorganisms is beneficial because it keeps the immune system both active and tolerant at the same time. A lack of exposure to environmental factors might contribute to an immune system that overreacts, potentially leading to systemic reactions such as those encountered in inflammatory diseases and allergies.
Netea: ‘In our daily lives, we are constantly exposed to various micro-organisms. This helps train our immune system, teaching it to recognize which microorganisms are dangerous