A study of the Yale University (United States) revealed that COVID-19 can trigger stronger inflammatory responses in men, causing changes in their functional immunity long after recovery.
After the body has dealt with a pathogen, does the immune system return to its previous state? Or does a single infection change it in a way that alters its response not only to a known virus, but also to the next viral or bacterial threat it encounters?
Study leader John Tsang, a professor of immunobiology and biomedical engineering at Yale, has long believed that the immune system returns to its previous state after a viral infection.
The onset of the COVID-19 pandemic in 2020 allowed him and his colleagues to test this theory. According to his research, published in the scientific journal ‘Nature’, the answer depends on the sex of the individual.
For the study, they systematically analyzed the immune responses of healthy people who had received the flu shot. Using that data, they then compared responses between those who had never been infected with SARS-CoV-2, the virus that causes COVID-19, and those he experienced mild cases, but recovered.
To their surprise, they found that the immune systems of men who had recovered from mild cases of COVID-19 responded more effectively to flu shots than women who had mild cases or men and women who had never been infected.
Essentially, the underlying immune status in men previously infected with SARS-CoV-2 was altered in a way that changed the response to a different SARS-CoV-2 challenge.
Different immune response
“This came as a complete surprise. Women tend to mount a stronger overall immune response to pathogens and vaccines, but they are also more prone to autoimmune diseases,” Tsang said.
The findings may also relate to an observation made early in the pandemic: men were much more likely to die by an exaggerated immune response compared to women after contracting the COVID-19 virus.
The new findings suggest that even mild cases of COVID-19 could trigger stronger inflammatory responses in men than women, leading to more pronounced functional changes in the male immune system, even long after recovery.
Their unbiased analysis of the state of the immune system down to the individual cellular level revealed several differences between recovered COVID-19 males and healthy controls and recovered COVID-19 females, both before and after receiving the flu vaccine.
For example, previously infected males produced more influenza antibodies and higher levels of interferons, produced by cells in response to infection or vaccination. In general, healthy women have stronger responses to interferons than men.
Understanding the persistent effects of COVID-19 on the immune system is critical, according to the authors, given that so far more than 600 million people have been infected worldwide and the occurrence of symptoms of persistent COVID-19 in some people remains a concern. great health concern.
“Our findings point to the possibility that any infection or immune challenge can change immune status set new benchmarks. An individual’s immune status is likely shaped by a multitude of previous exposures and perturbations.”
