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Building Long-term Immunity: Should It Be An Essential Part Of Each Prescription

Author: Dr. Mukesh Kochar

M.B.B.S, MD (General Medicine), Consultant Physician AMRI Medical Centre. Belle Vue Clinic. Bhagirathi Neo􀆟a Woman and Child Care Centre, Kolkata.

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The current global pandemic of COVID-19 has emphasized on the need of a strong immunity.  Different types of disease-forming organisms activate different parts of the immune system primarily. A strong immune system can be achieved by all vital nutrition and essential vitamins and minerals which will help to fight diseases naturally. Besides a healthy diet, daily exercise is also vital for a good immune system. Although, daily intake of nutrition is always not achieved and an intake of immunity booster can help to maintain it.

Keywords: Innate Immunity, Adaptive Immunity, Active Immunity, Passive Immunity



The immune system helps to protect the body from harmful substance by detecting and responding to antigens. Antigens are substance (usually proteins) that present on the outside of a pathogen. Non-living substance can also be antigens such as toxins, chemicals, drugs, and foreign particles (such as a splinter) [1].

Two components of immune system are innate and adaptive immunity (Table 1). The innate immunity occurs in all metazoans, while the adaptive immunity is only present in vertebrates [2].

Table 1: Parameters of Innate and Adaptive Immunity


Innate immune system

Adaptive immune system


Response is non-specific

Pathogen and antigen specific response


Exposure leads to immediate maximal response

Lag time between exposure and maximal response


No immunological memory

Exposure leads to immunological memory

Present in

Found in nearly all forms of life

Found only in jawed vertebrates


Innate immunity, also known as native immunity, which is widely distributed form of immunity. It is defined as the first line of defense against pathogens, representing a critical systemic response to stop infection and maintain homeostasis, contributing to the activation of an adaptive immune response [3].

Adaptive or acquired immunity is the active constituent of host immune response, mediated by antigen-specific lymphocytes. It is highly specific to a particular pathogen, including the development of immunological memory. Adaptive immunity is classified as ‘active’ or ‘passive’ [4]. Active immunity is acquired through the exposure to a pathogen, which triggers the release of antibodies by the immune system. Passive immunity is acquired through the transfer of activated T-cells derived from an immune host (antibodies) either artificially or through the placenta, requires booster doses for continued immunity as it is short lived.

The diagram given below shows classification of immunity [5].


Figure 1:  Divisions of Immunity


Role of Immunity in Recovering from Illness

The immune system of human is a complex and powerful defense mechanism; the foremost effective mechanisms of immune system depend upon characteristics of the infectious agents. The initial function of the immunity is to guard the body from pathogens, which are disease causing organisms as virus and bacteria. To achieve this function cell, tissue and protein within the immune system work together [6].

How immunity works?

The immune system must be ready to recognize pathogens. Pathogens have molecules, called antigens, on their surface. Antigens provides a sole signature for pathogen that permits immune system to identify pathogens and differentiate pathogens from body’s own cells and tissues. The immune system reacts in two ways when a pathogen enters into the body.

  1. Innate immune response: It identify certain molecules that are present on many pathogens. In response to action of infection, these cells react to signalling molecules which is released by the body. As a result, innate immune cells quickly start fighting an infection. Leading into an inflammation. The cells involved during these reactions not only kill pathogens but will also help activate cells involved in adaptive immunity.
  2. Adaptive immune response: It is slower than the innate response but is better in targeting specific pathogens. There are two main cell types involved during response: T cells and B cells. There are some T cells which kill pathogens and infected cells; other T cells help to regulate the adaptive immune response. The main function of B cells is to make antibodies against specific antigens. Antibodies (immunoglobulins) are protein that attach themselves to pathogens. This then signals immune cells to devastate the pathogen (figure 2).

When pathogen causes an infection it takes time for T and B cells to respond to these new antigens. These cells then develop memory for the pathogens once exposed to them, so that they are ready for the subsequent infections. Some T and B cells become memory cells due to adaptive immunity. Memory cells usually stay within the lymph nodes and then the spleen and “remember” particular antigens. If an individual is re-infected with the same pathogen again, these cells are now ready to rapidly and aggressively begin fighting the infection [7].


Figure 2: The immune response against invading pathogens


Supportive Care During Recovery

During COVID 19 outbreak it was observed that people with ‘weak’ immune system are at higher risk of getting affected by virus. Immune system is responsible for destroying viruses and germs that enter the body and protects from diseases. So it is important to take every measures possible to ensure that the immune system remains healthy and strong. Stronger immune system can be built with few lifestyle amendments.

Lifestyle changes to strengthen overall immunity

  1. Diet:  A good nutrition is the key to a healthy and strong immune system that provide protection against seasonal illness and other health problems. Gut and immune system goes hand-in-hand, means keeping gut healthy, to ensure healthy immune system. Therefore, including foods in diets that are gut-friendly, such as probiotics, fermented and cultured foods, and sprouted vegetables. Adding more amount of antioxidant-rich foods in diet that can help fight against cell damage and body invaders. Consuming a balanced diet that contains protein, fiber, vitamins, minerals, and other nutrients that boost the immune system and help support immune response and play a role in healthful eating style.
  2. Workout: There is powerful link between exercise and the body’s defense system. Practicing yoga, daily walk or regular exercise routine can help decrease your chances of developing any health issues. Regular exercise helps in the production and strengthening of white blood cells (WBCs) that helps to fight against disease. Exercise helps WBCs to circulating more rapidly, allowing them to detect harmful organism before they can cause any problem. Physical activity and good nutrition may help to minimise the risk of negative consequences of age-related immune dysfunction. [8]
  3. Sleep: Insufficient sleep can affect immune system. A protein called cytokines is released by immune system when body is in sleep mode, this protein helps to fight against infection and inflammation therefore its production needs to be increased once you are infected. Production of cytokines may reduce due to lack of sleep. You need at least 7-8hrs of sleep is needed, it will not only keep immune system healthy but also keeps body active throughout the day.
  4. Herbal diet: There are some herbs that help to boost your immunity.
  • Moringa- It is a herb that may ward off many health complications and helps to strength immunity. It contains high amount of vitamin C even more than oranges. It also contains some other important nutrients that helps in the strengthening of cells, muscles, tissues and helps in healing. Consuming moringa helps to increase the levels of calcium, iron, potassium and amino acids.
  • Neem- Since time immemorial, it is respected and wildly used to strengthen immunity. It has several properties like anti-viral, anti-bacterial and anti-fungal properties. Apart from that it also helps to keep the body from attacks by harmful pathogens. Neem purifies the blood by flushing away toxin and this helps to strengthen immunity.
  • Tulsi- It is also known as basil which is powerful germicide. Because of its phytochemicals and antioxidant, it can effectively locate germs, virus and bacteria the moment they enter body and destroy them.
  • Ashwagandha- It helps to decrease the stress level. Stress lowers immune response and make the body in the risk of viral infection.
  • Ginger- It is ancient remedy for common cold and flu. It contains gingerol - an antioxidant that strengthen immunity. It is good in preventing respiratory tract infection.
  • Turmeric- It contains curcumin (phytochemical) that helps in the removal of toxin from body and strengthen immunity to fight off germs and bacteria.   


Guidelines to Strengthen Immunity

Enhancing the body’s natural defense system (immunity) plays an important and significant role in maintaining optimum health. Importance of immunity gained importance during the outbreak of the global pandemic of COVID-19 in recent times. Various authorities and ministry of AYUSH recommended self-care guidelines for preventive health measures and boosting immunity.

The following measures are recommended by Ministry of AYUSH [9]:

  • Daily yoga and meditation in the morning for half an hour is beneficial.
  • Indian common spices like turmeric powder, coriander powder and garlic cloves are suggested in cooking.
  • Drink homemade herbal tea or decoction prepared using basil, cinnamon, dark pepper, dry ginger and raisins - a few times per day.


Recommended Lifestyle Interventions [10]:


  • Fiber‐rich, nutrient‐dense, antioxidant‐rich whole food plant foods such as green leafy vegetables (3‐5 servings/day), fruits (2‐4 servings/day), whole grains, legumes, nuts and seeds.
  • Food enriched with healthy fatty acids in fish, meat and eggs needs be in daily diet.
  • Limit salt consumption, soft drinks, or sodas.
  • Junk foods, processed fast foods and unsaturated fats should be strictly avoided.
  • Exercise regularly to maintain a healthy body weight.

Physical activity

  • Engage in moderate‐intensity aerobic physical activity (eg, brisk walk) 30 min‐1 hr/day or 150‐300 min per week, plus resistance exercise (eg, press‐ups, situps, and weights) for 1 h, two to three times/week on nonconsecutive days.
  • Exercise caution with patients in moderate stage of COVID‐19 who may be breathless on exertion.


  • Improving sleep hygiene, aiming for 7‐8 hours uninterrupted, restorative sleep every night.

Harmful substances

  • Avoid alcohol intake and smoking in a daily basis. This can damage the lungs.

Stress management

  • Adopt a variety of measures to keep stress levels low, including favourite music, videos, and movies.
  • Conversation with friends and family about life event should be shared to avoid anxiety, depression and mental health issues.
  • Use reliable sources, for any kind of information.
  • Minimize anxiety by limiting news, current affairs, and stressful drama.
  • Consider relaxation techniques such as deep breathing, meditation, Yoga, Tai Chi, and mindfulness, using apps or online resources.


Nutritional Care: Integral Part of Rehabilitation

Immunological disorders in critically ill patients is a serious challenge in critical care management, as its incidence increases risk of other secondary infections in ICU patients, eventually which increases their length of stay in hospitals [11]. Patients with persistent critical illness have a high mortality and a high risk of long term morbidity. From this perspective developing a comprehension of the underlying immune response in persistent critical illness in its context is fundamental of improving the management of these patients and avoiding complications.

Proper nutritional value and addition to the diet gives an extra advantage of recovery and protection against diseases which further helps the body to fight against the viral and bacterial infections. The immunological regulation and functioning require nutritional support post illness for recovery with vitamins, micronutrients playing the vital role. The roles of important vitamins and minerals are discussed as follows:

  • Vitamin C- An essential micronutrient for humans, vitamin C contributes to immune defense by supporting various cellular functions of both the innate and adaptive immune system. It supports the epithelial skin barrier function against foreign bodies harmful microorganisms and promotes antioxidant activity. Besides the antioxidant properties, it also aggregates in phagocytic cells, such as neutrophils, and can enhance chemotaxis, phagocytosis, generation of reactive oxygen species, and ultimately microbial killing. It is likewise required for apoptosis and clearance of the spent neutrophils from sites of infection by macrophages, thereby decreasing necrosis/NETosis and potential tissue damage [12].
  • Vitamin D- The vitamin exists in two forms, D2 (ergocalciferol) and D3 (cholecalciferol). The forms of vitamin D has number of effects on every cells of the the immune system. It is known to enhance innate cellular immunity through stimulation of expression of anti-microbial peptides [13]. Besides fighting directly against microbes, monocytes and other innate antigen presenting cells (APC), in particular dendritic cells (DC), are important targets for the immune modulatory effects of vitamin D. Antigen presenting cells are in charge for the induction of the adaptive immune reaction as they present antigens to T and B cells and are capable of regulating them by either immunogenic signals such as cytokines and expression of co-stimulatory molecules [14].
  • Vitamin B- The various forms of vitamin B participates in playing a vital role in cell functioning, energy metabolism, and proper immune function [15]. Vitamin B helps in activating the process of the innate and adaptive immune responses, leading to reduction in pro-inflammatory cytokine levels. This results in improving lung functioning, endothelial integrity, prevents hyper coagulation and further helps in reduction of the length of stay in hospital [16]. Vitamin B exhibit in different forms as Vitamin B1 (Thiamine), Vitamin B2 (Riboflavin), Vitamin B3 (Nicotinamide, Niacin), Vitamin B5 (Pantothenic acid), Vitamin B6 (Pyridoxine), Vitamin B9 (folic acid, folate) and Vitamin B12 (cobalamine) with different properties in maintaining the immune system; like, Folate is an essential vitamin for DNA and protein synthesis and in the adaptive immune response. Vitamin B12 or cobalamin is essential for red blood cell synthesis, nervous system health, myelin synthesis, cellular growth and the rapid synthesis of DNA [17].
  • Vitamin E- A potent lipid-soluble antioxidant, found in higher concentration in immune cells compared to other cells in blood, is one of the most effective nutrients known to modulate immune function. The importance has been observed in studies showing a reduction in inflammatory cytokines and improvement in T cell proliferation with vitamin E supplementation [18]. It prevents lipid peroxidation and the associated cell membrane damage. It may assist in the maintenance of membrane integrity, maintain signal transduction and production of key proteins and other mediators. Also directly affect the function of immune cells [19].
  • Vitamin A- A popular and important micronutrient that is known for its potential benefits for maintaining vision, promoting growth and development, and protecting epithelium and mucus integrity in the body. It is known as an anti-inflammation vitamin because of its important role in enhancing immune function in the body. Vitamin A exists in the form of retinol, retinal, and retinoic acid, among which retinoic acid shows the most biological activity. Studies have shown that important organs of body need constant dietary intake of the vitamin, and retinoic acid was shown both to promote the proliferation and to regulate the apoptosis of thymocytes. [20].
  • Zinc- An essential mineral that the body doesn’t produce on its own. Zinc is needed and crucial for many processes in the body like gene expressions, enzymatic reactions, immune cell functions, DNA and protein synthesis, wound healing and overall growth and development. It is necessary for cell signaling and a deficiency can lead to weakened immune response.
  • Selenium- A trace mineral, that is having fundamental importance to human health. Selenium is a component of selenoproteins and enzymes which have antioxidant properties that help to dissociate peroxides, preventing inflammation and heart disorders. Supplementation with selenium has shown immunostimulant effects, including an enhancement of proliferation of activated T cells [21].
  • Iron and Copper- Iron is an essential element for blood production. Its deficiency affects the capacity to have an adequate immune response. Iron is crucial for immune cells proliferation, especially lymphocytes, which is engaged in the generation of response against infection. Zinc and copper both are essential and the deficiency of either of them can increase the chances of bacterial infection. Copper is also responsible for production of red blood cells in association with zinc [22].


Case Study- Importance of Immunity Boosters During COVID-19 Outbreak

Recently, the world has witnessed a global pandemic, Coronavirus outbreak caused by the SARS-CoV-2 virus, which has mutated to allow human-to-human spread. When there was no approved vaccines and medicines for the viral infection, immunity played a vital role to save lives of people. Satisfactory levels of vitamins C, D and E are very important during coronavirus outbreak to diminish symptom burden and reduce the length of duration of respiratory infection. Research also supports a role for minerals such as zinc as they have antiviral effects and may improve immune responses and suppress viral replication [23].  The intake of adequate amounts of vitamins and minerals through diet is essential to ensure the proper functioning of the immune system. Fruits, vegetables, meat, fish, poultry and dairy products are good source of these vitamins and minerals. To support immune function during COVID-19 disease higher dietary intakes of vitamins D, C and E, zinc and omega-3 fatty acids was found to be beneficial.

Apart from the current pandemic, boosting immunity is also necessary for chronic illness like diabetes, bacterial infections, hepatitis etc. Strengthening the immune system is very crucial as it also maintains healthy gut with probiotics and helps in the fight against foreign bodies.



The current pandemic has given a clear message of the importance of immunity and its role in chronic diseases. It was observed that elder people, chronic disease patients and children were at more risk than younger individuals. As, elder people are immunocompromised and prone to infections, whereas the population is affected by malnutrition. Unhealthiness builds grimness, mortality, and causes critical financial effect on the medical services frameworks, while the monetary circumstance of a nation impacts all parts of ideal nourishment care. The expanded danger of dismalness and mortality brought about by hunger is an aftereffect of the expanded pace of contaminations, just as by postponed recuperation. A daily intake of healthy diet is much necessary and need of the hour. In present times, with the fast paced life and fast processed food with limited nutritional values are affecting our nutritional intake, and further affecting our health and immune system, that is causing infections and serious health issues. Recommended nutraceutical and immunity booster supplements in every prescription prescribed to a patient will give an added advantage of making a strong immune system and which will further help in the long run to fight against serious infections and also maintain the daily intake of essential vitamins, minerals and all important nutrients to be a part of daily diet. An immunity booster daily can change the whole scenario of the healthcare system by reducing mortality rate, hospital stay and be prepared in the near future. This initiative will change major concerns like malnutrition, compromised immunity, chronic diseases etc. in the long run.



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