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Published on: Apr 20, 2020
3 minute read
By: Dr Rajan Choudhary

Is Herd Immunity A Valid Strategy For COVID 19?

Yesterday we explained you what Herd Immunity means and how it works, today we will take the discussion further to determine whether it is effective and can be recommended in the current context.

COVID-19 currently does not have a cure or a vaccine. Lockdown is the only strategy that appears to be working. Could implementing policies that encourages herd immunity be used to accelerate immunity in the population without the need for a vaccine?

INFECTIVITY

For the strategy to work we need to know a few things about the virus. How infective is it? In one of our earliest blogs we discussed infectivity at length and determined that the R0 (infectivity) may be between 2 and 3. This means each person with the virus can infect around 2-3 people at a time. Whilst this is not as high as Mumps (10-12) it is much higher than the common flu. The higher the R0 the more people that need to be immunised before herd immunity is achieved. For COVID it is estimated that 70% of the population need to be infected.

This is based off our current testing. Due to shortages in testing kits, only testing those that have a high likelihood of being infected and poorly organised testing infrastructure in some countries, we are likely underestimating. The number of people infected may be much higher as we are missing those that are asymptomatic but still have the disease and are still passing the disease on.

MORTALITY

Secondly, we need to know the mortality from COVID-19. Early estimates of mortality were as high as 10%, as we had little data on how many people were truly infected, but as the number of infected cases rose, and testing amongst the infected and symptomatic population rose, a more accurate mortality has been found to be around 1%. There is a risk we may still be underestimating the true mortality, as some cities have noted a spike in cardiac deaths, and some evidence supports possible cardiac damage due to COVID. But from the data we have, we know its mortality is lower than MERS (34%) and SARS (10%) but more than influenza (0.1%).

estimates of the COVID-19 case fatality rate

Whilst we have some data on who is likely to suffer from severe COVID symptoms (elderly, immunocompromised, people with heart or lung problems) we still cannot accurately determine who will get severe COVID in the “low risk” population. Simply because someone is young and healthy does not mean they will not die from COVID.

LENGTH OF IMMUNITY

Third we need to know how long this immunity will last. Similar coronaviruses responsible for the common cold usually create immunity that lasts for a few months, which is why we often get the cold repeatedly. A virus is also very prone to mutations that can change the structure and functions of its proteins, proteins responsible for tagging, latching on to and entering cells. If the structure of these proteins changes enough, then our antibodies will not be able to bind on, and new types of antibodies will have to be made with a slightly different structure. This effectively means our bodies have to start from step 1 again to create immunity, and we have to make new vaccines. This mutation rate is why we have to make new vaccines every season for the flu.

LONG TERM COMPLICATIONS

Finally, we need to know if there are any long-term implications from a viral infection. Again, this is something we do not know yet, as the virus has only been around for a few months. There may be implications for the cardiovascular system, long term breathing problems or more. And even if the complication rate appears relatively low (say, 1%), if millions of people are allowed to get infected, by definitions thousands or tens of thousands of people will have these complications, complications that can lead to issues later in life or an early death.

CONCLUSION

So, is herd immunity a viable strategy for COVID? Without a safe vaccine the general consensus appears to be no.

We don’t know how infective the virus really is or how many people it has infected

A 1% death rate is still very high. This means for every 100 people to be infected; one will die. This would mean hundreds of thousands of people dead in a country with a population over 10 million. It is unacceptably high.

If the death rate is 1%, then hospitalisation rate is likely higher. Almost all countries do not have capacity to have 1% of the population in hospital. Overwhelming the healthcare system will lead to poorer care, and worse care for those who do not have COVID. Leading to more people coming to serious harm or dying as a result of poor healthcare, not because of COVID.

We don’t know the long-term effects of COVID. By purposefully infecting people instead of waiting for a vaccine we may be causing unnecessary damage to a person’s health that only becomes apparent later in life. But this is speculation as we do not currently know if COVID has long term effects,

We don’t know if all of the risks above will amount to anything. The immunity may not last long enough, leading to another spike in infections and mortality.

Mass vaccination appears to be the safest strategy. And though human clinical trials have started on a number of vaccines, we are still months away from deployment. Until then we should not come out of lockdown prematurely, not until we have received an unbiased assessment from public health officials that states it is safe.

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Nutritional Deficiencies in Indian Kids: Recognizing, Preventing & Overcoming “Hidden Hunger”

Every parent wants their child to grow up healthy — tall, strong, smart, and full of energy. But in India, many kids suffer from what is known as “hidden hunger.” It means that even though they are eating, their diet lacks essential nutrients. These nutritional deficiencies can affect growth, learning, immunity, and long-term health. In this blog, we’ll explore the major nutritional deficiencies in Indian kids, what causes them, how to detect them, and what parents can do. Let’s dive into nutritional deficiencies in Indian kids.

What Are the Most Common Nutritional Deficiencies?

Based on recent research and national surveys, the following are among the most widespread deficiencies in Indian children:

Iron Deficiency / Anaemia
A large percentage of Indian kids (especially under-5s) have low hemoglobin and low iron stores. Anaemia can cause tiredness, slow cognitive development, and lowered immunity. Lippincott Journals+2PMC+2
Vitamin A Deficiency
Vitamin A is essential for good vision, immunity, and healthy cells. Many children under 5 show sub-clinical deficiency; some show clinical signs like night blindness. Lippincott Journals+1
Iodine Deficiency
Iodine is critical for thyroid hormone production, which affects brain development. Lack of iodine can lead to goitre, delayed mental development, and poor school performance. Lippincott Journals+2thyrocare.com+2
Vitamin D Deficiency
Even though India is sunny, many children have low vitamin D — due to indoor living, limited sun exposure, skin coverage, or dietary gaps. This impacts bone health, growth, and risks rickets. PMC+1
Protein-Energy Malnutrition (PEM)
In poorer or marginalized communities, children may not get enough protein or calories. This leads to underweight, wasting, stunting, and weakened immunity. Lippincott Journals+2HDFC ERGO+2
Other Micronutrients (Vitamin B12, folate, zinc etc.)
Deficiencies in B12 & folate can affect cell division, blood production, nerve function; zinc deficiency weakens immunity & slows growth. PMC+2nanhedil.com+2

Why Do These Deficiencies Happen?

Understanding the causes helps in prevention:

Dietary Factors
Many diets are heavy in cereals or starches but low in diversity. Meals may lack fruits, vegetables, animal-source foods (meat, eggs, fish) or fortified products.
Bioavailability of Nutrients
Even when foods contain nutrients, they may not be absorbed well. For example, plant-based iron is less readily absorbed, phytates in grains and legumes can reduce absorption.
Socioeconomic Constraints
Poverty, food insecurity, access issues, lack of awareness, and sometimes traditional/cultural food beliefs limit access to nutrient-rich foods.
Living Conditions and Health
Frequent infections, parasitic infestations, poor hygiene, etc., can increase nutrient loss or demand. Also sunlight exposure (important for vitamin D) is inadequate in many cases.
Gaps in Implementation of Prevention Programs
Though India has multiple programs (fortification, supplement distribution, ICDS, National Nutrition Mission etc.), challenges remain in reach, compliance, quality, and behavioural change.

Effects of Nutritional Deficiencies

These deficiencies have short-term and long-term effects:

Growth stunting (children don’t reach their full height potential)
Wasting (low weight for height), underweight
Impaired cognitive development & learning difficulties
Weak immune system ? more infections
Delayed motor skills, poor school performance
Bone deformities (rickets, weak bones)
Poor quality of life; in severe cases, increased mortality

How to Detect & Diagnose Early

Taking action early helps avoid permanent harm. Key strategies include:

Regular growth monitoring: Checking weight, height, BMI for age
Look for signs: Pale skin or lips, tiredness, delayed milestones, frequent illness, bone pain or deformities (knees bowing, wrist/ankle enlargement)
Lab tests:
- Haemoglobin & complete blood count
- Serum ferritin for iron stores
- Serum levels for vitamin A (retinol)
- 25-OH vitamin D test
- Serum B12, folate
- Urinary iodine excretion or salt iodine test
- Protein / albumin levels

Using broad vitamin profiles (like those from Thyrocare) can help screen for multiple deficiencies in one go.

Foods, Diet & Prevention: What Parents / Caregivers Can Do

Here are practical steps parents can take:

Diversify diet: Include pulses, legumes, eggs, dairy, meat (if non-vegetarian), fish; plenty of green leafy vegetables & fruits.
Fortified foods: Use iodised salt; choose cereals / milk products fortified with vitamins & iron.
Sunlight exposure: Encourage outdoor activities; even short daily sun exposure (face, arms) helps vitamin D.
Supplementation when needed: Under doctor guidance, provide vitamin A doses, iron/folic acid, vitamin D etc., especially in high-risk children.
Hygiene & health care: Prevent worm infections, diarrhoea etc. which can drain nutrients. Ensure vaccinations.
Education & awareness: Teach families importance of nutrition, balanced meals, what local foods can provide what nutrients.

What Parents Should Ask Healthcare Providers

Ask whether your child needs screening for deficiencies (e.g., iron, vitamin A, D, B12).
If lab tests are suggested, check whether it’s comprehensive or narrow, cost, and follow-up.
Seek help for dietary planning, perhaps from nutritionists or public health bodies.
Learn about local government/NGO programs—free or subsidized supplementation or fortified food programs.

When to Seek Medical Help

If your child has:

Persistent anaemia symptoms (very pale, lethargic)
Growth issues (falling off growth charts)
Bone deformities or pain
Severe or recurrent infections
Unusual signs like night blindness, goitre

Then get a medical evaluation. Early intervention can make a big difference.

Conclusion & Call to Action

Nutritional deficiencies in Indian kids are common—but many are preventable or treatable. By recognizing risks, ensuring good diet, doing appropriate lab tests, and using supplements or fortified foods when needed, children can grow healthier, smarter, and stronger.

If you’re concerned that your child may have one or more of these deficiencies, talk to a trusted pediatrician or nutritionist, and consider getting a comprehensive vitamin & nutrition profile done (for example through Thyrocare or SecondMedic) to know exactly where improvements are needed. Don’t wait—every child deserves a strong foundation.

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