Immune response of women to covid better than that of men, claim studies2 min read . Updated: 28 Aug 2020, 10:31 AM IST
- The scientists said that collectively, available data suggest that vaccines and therapies to elevate T-cell immune response to SARS-CoV-2 might be warranted for male patients, while female patients might benefit from therapies that dampen innate immune activation early during disease
Women have better immune response against covid-19 in comparison to men, a new scientific study has indicated.
The study published in Nature Journal and conducted by Women's Health Research at Yale University has found that men are more likely to suffer from severe illness and die of covid-19 than women.
In this study, the researchers found that female patients mounted significantly more robust T-cell activation than male patients during SARS-CoV-2 infection, which was sustained in old age.
T-cells, also known as T-lymphocytes, are one of the major components of the adaptive immune system of human body. T-cells directly kill infected host cells, activating other immune cells.
“Importantly, we found that a poor T-cell response negatively correlated with patients’ age and was associated with worse disease outcome in male patients, but not in female patients," the study said.
The study was done on about 98 patients admitted in the Yale New Haven Hospital with mild to moderate disease with confirmed Covid-19 tests. The average age of patients was 61 to 64 years.
A growing body of evidence indicates sex-based differences in clinical outcomes of covid-19 infection. However, whether immune responses against SARS-CoV-2 differ between sexes, and whether such differences explain male susceptibility to covid-19, is currently unknown, the scientists said.
“Immune landscape in covid-19 patients is considerably different between the sexes, and these differences may underlie heightened disease susceptibility in men," the study said.
The researchers collected nasal, saliva, and blood samples from non-infected control subjects as well as patients with the disease. The team followed patients over time to observe how initial immune responses differ in patients who recover from the disease and those who progress to worse stages of the disease.
The research was also published independently by the Yale University. When comparing male and female patients, the researchers found key differences in the immune response during the early phases of infection.
“These differences included higher levels for men of several types of inflammatory proteins called cytokines, including two known as IL-8 and IL-18. Cytokines are deployed as part of the body’s innate immune reaction," the Yale University article said.
This a first general counterattack to invading pathogens, in which immune cells are called to the site of an infection, creating inflammation of the affected tissue as a physical barrier against the invading pathogen to promote healing, it said.
“However, in severe cases of covid-19, an excessive buildup of cytokines, referred to as a 'cytokine storm', causes fluid to build up in the lungs, depriving the body of oxygen and potentially leading to shock, tissue damage, and multiple organ failure. The earlier higher concentrations of cytokines in men make these outcomes more likely," the Yale University article said.
In contrast, the researchers found that female patients had more robust activation than men of T-cells, white blood cells of the adaptive immune system that can recognize individual invading viruses and eliminate them.
Observations over time revealed that poor T-cell responses in men led to worsening of the disease. When female patients had highly elevated innate cytokine levels, they too did worse. In addition, older men — but not older women — were observed to have significantly worse T-cell responses than younger patients, the article said.
The scientists said that collectively, these data suggest that vaccines and therapies to elevate T-cell immune response to SARS-CoV-2 might be warranted for male patients, while female patients might benefit from therapies that dampen innate immune activation early during disease.