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Published on: Apr 19, 2020
3 minute read
By: Dr Rajan Choudhary

What Is Herd Immunity With Respect To Covid19 ?

Herd immunity: the basics

Many countries have been in lockdown for over a month, and some have tried to begin the discussion of an exit strategy. We know that remaining in lockdown continuously is not a feasible strategy, as many people have been suffering economic consequences from the stringent lockdown measures, and many countries have been providing significant monetary and fiscal support for people and businesses at risk. But leaving lockdown too early has its own consequences.

Almost all public health professionals will agree that the lockdown has been able to significantly reduce infection rates and reduce the pressure on our healthcare systems. By taking this early victory and prematurely ending lockdown we risk another wave of infections, reintroducing lockdown, and having an overall negative effect on the general health of the populous.

So what can we do? One exit strategy that has been touted recently is herd immunity. To understand how to may work for COVID we must understand what epidemiologists mean by herd immunity.

IMMUNITY

Our body’s immune system fights against invading organisms such as bacteria and viruses. For a more in-depth discussion you can have a look at previous blogs on Vaccines and Boosting the Immune system. The immune system is very competent and has mechanisms to theoretically recognise any protein tags that do not belong to that person’s cells, even protein tags that do not currently exist in nature. This gives the immune system the ability to theoretically recognise nearly any invading organism that has existed or will ever exist.

The immune system goes beyond this as well and produces “memory cells”. These remain in the blood after an infection for a long time; in some cases, it can even be lifelong. When a second infection occurs from the same organism the immune system jumps into action and is able to produce antibodies against the invader almost immediately. This can neutralise the invader before it has a chance to replicate, cause severe symptoms and harm the body. Sometimes we never realise we have been infected as the infection never gets a chance to cause any damage.

Importantly, if the invader cannot replicate in our body, then its ability to spread to other people is also reduced. For example, respiratory viruses can rapidly replicate in our lungs and be transmitted when we cough or sneeze. By eliminating the virus before it can replicate extensively the number of viral particles in each cough and sneeze is reduced, reducing the chances of another person catching the infection.

This is the basis of how vaccines work and is covered in depth in the two part blog.

HERD IMMUNITY

If our immune system is so competent, why do we need to worry about infections at all? Surely we can all get infected and gain immunity. In an ideal world where everyone was healthy this may be true. But there are many people who do not have fully functioning immune systems. These people are immunocompromised and can be for many reasons.

Chemotherapy and radiotherapy for cancer destroys rapidly dividing cells such as cancer cells. Unfortunately, it also hits other dividing cells, such as hair follicles, gut lining and the bone marrow, which produce the white blood cells that give us immunity. Chemotherapy patients are very susceptible to even the mildest of infections. Even if a mild infection is suspected, they are treated aggressively with antibiotics, as their lowered immune systems can become overwhelmed very quickly.
Sometimes doctors advise patients to take medication that purposefully dampens the immune system. This is necessary for transplant patients, where the host immune system attacks the donor organ as it does not belong to the host, or in autoimmune disorders, where the immune system attacks the host by mistakenly recognising it as an “invader”.
Taking steroids long term has a similar effect, and is used quite commonly for skin disorders, asthma, COPD, and other inflammatory conditions.
People with various chronic illnesses can have reduced immunity as a result of the illness. High sugar levels associated with poorly controlled diabetes can cause worsening organ function, including the immune system. These patients are more susceptible to infections.
Finally, some people do not have fully functioning or welldeveloped immune systems for a variety of reasons, inherited or acquired. As we get older, the immune system function decreases, and simple infections can be devastating.

In all of these cases the ability to recognise invading organisms, destroy them and form immunity is hampered. Vaccination, one way of inducing immunity without causing the person to suffer from a full-blown infection, can also be ineffective in these patients, and some vaccines can be dangerous if used incorrectly. So how do we protect these vulnerable patients?

HERD IMMUNITY

This is where we go back to the earlier point. Immunity in healthy people can reduce or even prevent the spread of infection from one person to another. The number of healthy people outnumber the number of vulnerable, immunocompromised ones. Therefore, if we induce immunity in most people, the infection will simply not spread to the vulnerable ones. We don’t have to immunise everyone, just enough to prevent transmission. This is called herd immunity. This is why we immunise everyone with flu vaccines even those that are healthy and will survive a full blown infection. Because by preventing these people from inadvertently spreading the flu, they will protect those that we cannot immunise.

Does herd immunity work? For most other diseases, yes. It depends on how the disease is spread, and how infective it is. For measles, you need to immunise 19 out of 20 people to achieve herd immunity, because it is so infective. But once herd immunity was achieved death rates were drastically reduced. With the advent of anti-vaccine campaigns, particularly against MMR, this herd immunity has been lost, and many vulnerable children (and adults) who do not have fully functioning immune systems are now contracting this virus and dying from a preventable disease.

It can be achieved for pandemics as well. Norway was able to achieve partial herd immunity to H1N1 (swine flu) through a vaccination program and natural immunity. Vaccines are the best method for achieving herd immunity without extremely high death rates. We have already covered the issues with making a vaccine, and why it takes such a long time, in our previous blog

From reading this blog you should now have an understanding of what herd immunity is, and why it is important in protecting those that are vulnerable to infections. In our next blog we will look at why herd immunity may not be the solution for COVID-19.

Dr Rajan Choudhary, UK, Chief Product Officer, Second Medic Inc

www.secondmedic.com

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Best Home Remedies for Glowing Skin

Glowing skin is not simply a cosmetic goal. It is a visible reflection of skin health, hydration, and cellular repair. While the market is flooded with serums and treatments, dermatologists consistently observe that the most sustainable skin glow comes from consistent, simple, and evidence-supported practices. The good news is that many of the most effective ingredients are already available in an Indian kitchen.

Why Skin Loses Its Natural Glow

Before applying any remedy, understanding the root cause of dull skin is essential. Dermatologists identify the following as the most common triggers in the Indian context:

Cause	Effect on Skin
Pollution and sun exposure	Oxidative stress, pigmentation, uneven tone
Dehydration	Reduced elasticity, dryness, dullness
Poor diet and nutrient deficiency	Slowed cell renewal, loss of radiance
Disrupted sleep	Impaired skin repair, dark circles, puffiness
Hormonal imbalance	Acne, oiliness, pigmentation
Harsh skincare products	Damaged skin barrier, redness, sensitivity

Identifying and addressing the underlying cause is as important as applying any topical remedy. Skin that appears dull despite consistent care often signals an internal factor requiring dietary or medical attention.

Which Home Remedy is Best for Glowing Skin?

Among all widely used natural ingredients, raw honey combined with aloe vera gel is considered the most universally effective home remedy for glowing skin. Honey acts as a humectant, drawing moisture into the skin, while its antibacterial and antioxidant compounds protect against environmental damage. Aloe vera complements this by delivering vitamins A, C, and E directly into the skin, supporting collagen synthesis and reducing inflammation.

This combination works across all skin types, requires no preparation time, and demonstrates consistent results in clinical observations relating to skin hydration and barrier repair. Applied three times a week for 15 to 20 minutes, this remedy produces visible improvement in skin texture and brightness within two to three weeks of regular use. For individuals with oily or acne-prone skin, aloe vera used alone without honey is the preferred option as it is non-comedogenic and lightweight.

Top Home Remedies for Glowing Skin by Skin Type

One of the most significant gaps in standard advice is that remedies are rarely matched to skin type. Applying the wrong ingredient can worsen the skin condition rather than improve it. Dermatologists recommend the following skin-type specific approach:

Skin Type	Best Remedy	Key Benefit	Frequency
Dry Skin	Raw honey and milk paste	Deep hydration, lactic acid exfoliation	3 times per week
Oily Skin	Multani mitti with rose water	Sebum control, pore tightening	2 times per week
Combination Skin	Aloe vera gel	Balances moisture without clogging pores	Daily
Sensitive Skin	Oat flour and plain yogurt pack	Soothes inflammation, gentle exfoliation	2 times per week
Normal Skin	Turmeric and honey mask	Antioxidant boost, brightening	2 to 3 times per week
Dull or Pigmented Skin	Potato juice or tomato pulp	Natural kojic acid, reduces pigmentation	3 times per week

Matching the remedy to skin type is the single most important factor in achieving consistent results from any natural skincare routine.

Which Kitchen Ingredients Work Best for Skin Glow?

Several common Indian kitchen ingredients carry clinically recognised skin benefits. The mechanism behind each ingredient matters as much as the application method:

Turmeric (Haldi): Contains curcumin, a potent antioxidant and anti-inflammatory compound. Curcumin inhibits melanin synthesis, which helps reduce pigmentation and uneven skin tone over time. Used as a paste with milk or honey, turmeric is one of the most researched natural brightening agents.

Raw Milk: Contains lactic acid, a naturally occurring alpha hydroxy acid (AHA) that gently exfoliates dead skin cells, stimulates collagen production, and improves skin luminosity. Applying raw cold milk with a cotton pad and leaving it for 15 minutes is a simple and effective brightening practice.

Besan (Gram Flour): Functions as a mild physical exfoliant and oil absorber. Mixed with turmeric and rose water, besan-based face packs have been used across Indian households for generations and remain dermatologically appropriate for most skin types.

Aloe Vera: Rich in polysaccharides that support skin hydration and mucilaginous compounds that form a protective barrier. Clinical data supports its use in reducing UV-induced skin damage and accelerating epidermal repair.

Potato Juice: Contains catecholase, an enzyme with mild skin-lightening properties. Particularly useful for reducing dark circles, tan lines, and post-inflammatory hyperpigmentation.

How to Get Glowing Skin Naturally in One Week

Most competitors list remedies without telling readers how to actually use them together. The following 7-day routine is structured to progressively address cleansing, exfoliation, hydration, and brightening within a single week:

Day	Morning	Evening
Day 1	Raw milk cotton pad cleanse	Aloe vera gel application
Day 2	Rose water toner	Honey and aloe vera mask (15 min)
Day 3	Raw milk cleanse	Turmeric and honey mask (10 min)
Day 4	Rose water toner	Aloe vera gel application
Day 5	Raw milk cleanse	Besan, turmeric and rose water pack (15 min)
Day 6	Rose water toner	Potato juice on dark spots (20 min)
Day 7	Raw milk cleanse	Honey and aloe vera mask (15 min)

This routine uses no more than three to four ingredients across the entire week, minimising the risk of ingredient overload or skin irritation. Always perform a patch test on the inner forearm before applying any new ingredient to the face.

Lifestyle Habits That Support Glowing Skin From Within

Topical remedies address the surface. Skin glow that is deep and lasting is primarily determined by internal health factors that all four competitor articles fail to address:

Hydration: Dermatologists observe that inadequate water intake is the single most common and most overlooked cause of dull skin among Indian adults. A minimum of 2.5 to 3 litres of water daily supports cellular metabolism and maintains skin turgor.

Diet: Skin cells require vitamins C, E, and A along with zinc and omega-3 fatty acids for repair and renewal. Indian dietary staples such as amla (Indian gooseberry), carrots, spinach, walnuts, and flaxseeds provide these nutrients in bioavailable forms. Reducing refined sugar intake is equally important, as excess glucose triggers glycation, a process that breaks down collagen and accelerates skin ageing.

Sleep: The skin's repair cycle peaks during deep sleep between 11 PM and 3 AM. Chronic sleep deprivation elevates cortisol, which degrades collagen and increases inflammatory skin conditions. Clinical specialists recommend seven to eight hours of uninterrupted sleep as a non-negotiable component of any skin improvement plan.

Gut Health: Emerging dermatological research on the gut-skin axis confirms that dysbiosis (imbalance of gut bacteria) is linked to acne, rosacea, and dull skin. Incorporating fermented foods such as curd and buttermilk into the daily diet supports gut microbiome balance, which in turn improves skin clarity.

Home Remedies to Avoid: What Dermatologists Warn Against

This section exists in none of the competing articles and represents the most clinically important addition to this topic. Several widely promoted "natural" skin remedies are actively harmful:

Lemon juice directly on skin: Lemon juice has a pH of approximately 2, far too acidic for direct skin application. It disrupts the skin's natural acid mantle (pH 4.5 to 5.5), causes photosensitivity, and can result in chemical burns or permanent pigmentation when skin is exposed to sunlight post-application.

Baking soda: Despite its popularity on social media, baking soda has an alkaline pH of 9, which severely disrupts the skin barrier, strips natural oils, and causes microbial imbalance on the skin surface.

Toothpaste on pimples: Toothpaste contains fluoride, menthol, and hydrogen peroxide, none of which are formulated for skin. It causes contact dermatitis, dryness, and post-inflammatory hyperpigmentation, particularly on Indian skin tones.

Undiluted essential oils: Applying undiluted tea tree oil, lavender oil, or any essential oil directly on the face without a carrier oil causes irritant contact dermatitis and skin sensitisation.

Dermatologists advise that if a remedy causes stinging, redness, or visible irritation, it should be discontinued immediately regardless of how widely it is recommended online.

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