New Delhi, November 19 (IANS). Immunity is often thought of as a straight line, either strong or weak. But scientific research suggests that our immune system actually works like a curve, with sudden ‘dips’ with the pressures of time, season, age, stress, sleep and infection. This pattern is called ‘immunity drop curve’ in the scientific world.
According to research published in Nature Reviews Immunology in 2021, the body’s immunity never remains stable; It keeps rising up and down and sometimes even falls suddenly. This is why two people living in the same environment are affected differently by the same virus.
If we look at the ‘immunity drop curve’ season wise, it is most clearly visible in winter. 2020 research from Harvard Medical School suggests that as the cold increases, vitamin D levels in the body drop, the mucosa layer of the nose weakens and viruses remain active in the air longer. Due to this, the curve of our immunity starts bending downwards. This is the reason why cases of flu, viral fever and cold reach their peak in many countries between November and February.
Age is also a big component of this curve, as a 2019 study from Stanford University suggests. This study shows that immune T cells slow down after the age of 40 and this decline accelerates after the age of 60. This means that the “downward slope” of the curve becomes more frequent and steeper as age increases. This is why older people come under the influence of a virus more quickly and younger people recover quicker.
Interestingly, the immunity drop curve is not just caused by natural factors—it is also influenced by micro-factors in our lifestyle. One study found that the lack of sulfur-rich vegetables, high-fiber and antioxidants in the diet weakens the intestinal microbiome. Because about 70 percent of immunity is controlled by the gut, even small mistakes in diet can lead to a dip in the curve.
The pressure of infection keeps changing this curve. The curve dips deeply when the body first fights a virus, but it suddenly rises with recovery—this is called the immune boost phase. The same pattern was clearly seen in Covid-19, where immunity remained unstable for a few weeks even after mild infection.
–IANS
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