Why does prolonged stress impair the effectiveness of influenza vaccines?

💡 Explanation

Prolonged stress leads to elevated cortisol levels, causing immunosuppression via the glucocorticoid receptor pathway, therefore decreasing vaccine efficacy rather than immune cell depletion, complement exhaustion, or innate receptor changes, because cortisol directly interferes with immune signaling and reduces inflammation.

• During pregnancy, a surge in placental hormones sustains the endometrium. Which mechanism explains why menstruation ceases despite the typical 28-day ovarian cycle's hormonal fluctuations?
• Why does administering broad-spectrum antibiotics often impair digestive efficiency within the human small intestine?
• In a neuron experiencing tau protein aggregation linked to neurodegenerative disease, which mechanism explains why the ubiquitin-proteasome system's (UPS) degradation rate slows despite increased ubiquitination?
• Which outcome results when a granulosa cell loses its ability to express aromatase during the mid-follicular phase?
• Why does administering supplemental oxygen to a patient with severe chronic obstructive pulmonary disease (COPD) sometimes paradoxically worsen their hypercapnia, leading to respiratory acidosis?
• Why does nociceptive pain, resulting from a deep tissue injury, often present as a broader, less precisely localized sensation compared to acute cutaneous pain from a paper cut?