• Published on: Nov 13, 2020
  • 2 minute read
  • By: Dr Rajan ( Medical Second Opinion Cell)

What Are Some Common Side Effects Of The COVID-19 Vaccine?

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COVID Vaccine, the Pfizer update

On Monday Pfizer announced to the world the vaccine, once it has been developing with Germany's BioNTech, was found to be more than 90?fective. If this is substantiated, it may be possible for countries to receive the vaccine before the end of the year.

The Vaccine is an mRNA Vaccine, a novel method that introduces viral RNA into the body via a viral coat. The vaccine is incorporated into the person's cell, where the viral RNA is read and viral proteins are produced, including the coronavirus coat proteins. As the body reads and recognizes these proteins, it produces antibodies against these viral proteins and activates immune T cells against the virus.

The Pfizer results are based of a phase 3 clinical trial with 43, 538 participants with a diverse background. In this trial, the participants were split between those receiving a vaccine, and those who received a placebo with no effect. The vaccine is administered in two parts, with a 90?ficacy obtained 7 days after the second dose. This would mean a person is vaccinated just 28 days after the initial vaccination.

The FDA usually looks for a minimum 50?ficacy in vaccination when approving new vaccines. It may surprise you that the annual flu jab is also estimated to be 50?fective. The data from Pfizer was verified by an external, independent Data Monitoring Committee. It used data from 94 patients enrolled in the trial and subsequently developed COVID. It is from this groupset that 90% of efficacy is obtained. This is not the final data analysis, and further publications are expected in late November, with a potential FDA Emergency Use Authorisation approval if the data continues to show promise.

If approved, Pfizer has the ability to make 50 million shots before the end of the year, and 1.3 billion by the end of 2021. Many countries are clamoring for their fair share of these limited resources; the US has already negotiated 200m shots, UK 50m, and Germany (one of the major financers for the Pfizer vaccine) over 300m for European Countries.

We should emphasize that rapid vaccine development on this scale at this speed was unheard of prior to COVID. Usually, the animal studies for vaccines can take 1-2 years. In that time Pfizer and others have managed phase 1-3 clinical trials in humans, something that usually takes upwards of 10 years.

There are many unanswered questions that remain from this information.

  1. How safe is the vaccine? Whilst safety information was not published, overall the vaccine appears to have minimal side effects. This is particularly difficult to state however since mRNA vaccines have never been used in people before.
  2. Does the vaccine prevent transmission? In theory, yes. If you are immunized the replication of the virus should be limited significantly, so the number of viruses in each cough will be much lower. However, we do not have data to prove that there is no transmission, but that is also because we have very little data overall.
  3. How long does the protection last? This is a very critical question. The 90?fectiveness rate was calculated just 7 days after the second shot, but it is likely this will change as data is collected over the long term. Some studies have suggested the antibody response fades within months following COVID infection. T Cell immunity on the other hand can stay for years, and it may be the effectiveness of creating a T cell immunity that dictates just how good this vaccine will be .
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Importance of Hydration for Organs: How Water Keeps the Body Functioning

Water is the most essential nutrient for human survival, yet it is often the most neglected. Every cell, tissue and organ in the body depends on adequate hydration to function properly. The importance of hydration for organs becomes clear when we understand how even mild dehydration can disrupt critical physiological processes.

In India’s climate, with high temperatures and humidity in many regions, dehydration risk is especially high, making conscious hydration a daily health priority.

 

Why Water Is Vital for the Human Body

The human body is made up of approximately 60 percent water. This water:

  • transports nutrients and oxygen
     

  • regulates body temperature
     

  • removes waste products
     

  • supports metabolic reactions
     

Without adequate hydration, organ systems begin to struggle.

 

Hydration and Kidney Health

The kidneys are among the most hydration-dependent organs.

Proper hydration:

  • helps kidneys filter blood efficiently
     

  • flushes out toxins and waste
     

  • reduces risk of kidney stones
     

Chronic dehydration forces kidneys to concentrate urine, increasing strain and long-term damage risk. According to Indian Council of Medical Research data, dehydration is a major contributor to kidney stone formation in India.

 

Brain Function and Hydration

The brain is highly sensitive to hydration levels.

Even mild dehydration can cause:

  • headaches
     

  • difficulty concentrating
     

  • memory issues
     

  • irritability
     

Studies published in the Lancet show that dehydration negatively affects cognitive performance and mood, even before thirst becomes noticeable.

 

Heart and Circulatory System

Hydration plays a critical role in cardiovascular health.

Adequate water intake:

  • maintains blood volume
     

  • supports smooth circulation
     

  • reduces strain on the heart
     

Dehydration thickens blood, making the heart work harder and potentially increasing the risk of low blood pressure, dizziness and cardiovascular stress.

 

Digestive System and Hydration

Water supports digestion at every stage.

It helps:

  • break down food
     

  • absorb nutrients
     

  • prevent constipation
     

Chronic low water intake is linked to digestive discomfort, bloating and poor gut motility.

 

Liver Function and Detoxification

The liver relies on water to:

  • metabolise nutrients
     

  • detoxify harmful substances
     

  • support metabolic balance
     

Inadequate hydration slows detoxification processes and increases metabolic strain.

 

Muscle and Joint Health

Muscles and joints contain significant water content.

Hydration:

  • prevents muscle cramps
     

  • supports joint lubrication
     

  • reduces injury risk
     

Dehydrated muscles fatigue faster and recover more slowly.

 

Skin as an Organ and Hydration

The skin is the body’s largest organ.

Adequate hydration:

  • maintains skin elasticity
     

  • supports barrier function
     

  • reduces dryness and irritation
     

While water alone is not a cure for skin problems, chronic dehydration worsens skin health.

 

Hydration and Immune Function

Water supports immune health by:

  • enabling transport of immune cells
     

  • aiding removal of toxins
     

  • supporting lymphatic circulation
     

WHO recognises hydration as a foundational element of immune system support.

 

Effects of Dehydration on Multiple Organs

Dehydration affects the body systemically.

Common effects include:

  • fatigue
     

  • dizziness
     

  • reduced urine output
     

  • dark-coloured urine
     

  • dry mouth and eyes
     

Severe dehydration can lead to organ failure if untreated.

 

Why Dehydration Often Goes Unnoticed

Many people confuse thirst with hunger or fatigue.

Risk factors include:

  • busy work schedules
     

  • excessive caffeine intake
     

  • high temperatures
     

  • inadequate fluid intake
     

By the time thirst is felt, dehydration has already begun.

 

Hydration Needs Vary by Individual

Water requirements depend on:

  • age
     

  • body size
     

  • physical activity
     

  • climate
     

  • health conditions
     

General guidelines suggest 2–3 litres daily for adults, but individual needs may vary.

 

Hydration and Chronic Disease Prevention

Proper hydration supports prevention of:

  • kidney disease
     

  • urinary tract infections
     

  • constipation
     

  • heat-related illness
     

NITI Aayog and WHO highlight hydration as a basic preventive health measure.

 

Best Practices for Staying Hydrated

Effective hydration strategies include:

  • drinking water regularly throughout the day
     

  • increasing intake during heat or physical activity
     

  • consuming water-rich foods such as fruits and vegetables
     

  • limiting sugary and caffeinated beverages
     

Consistency matters more than quantity in a single sitting.

 

Signs You May Need More Water

Watch for:

  • frequent fatigue
     

  • headaches
     

  • dry skin
     

  • reduced urination
     

  • poor concentration
     

These are early indicators of dehydration.

 

Role of Preventive Health Awareness

Preventive healthcare focuses on simple daily habits.

Hydration:

  • costs nothing
     

  • supports every organ
     

  • reduces disease risk
     

Small habits deliver large long-term benefits.

 

When to Seek Medical Advice

Consult a healthcare professional if experiencing:

  • persistent dehydration symptoms
     

  • kidney or urinary issues
     

  • dizziness or fainting
     

  • chronic fatigue
     

Underlying conditions may require medical evaluation.

 

Conclusion

The importance of hydration for organs cannot be overstated. Water supports kidney filtration, brain function, heart circulation, digestion, immunity and overall metabolic balance. Even mild dehydration disrupts organ performance and increases health risks over time. In busy modern lifestyles, consciously prioritising daily hydration is one of the simplest and most effective ways to protect vital organs and maintain long-term health. Consistent water intake is not just a habit—it is a foundation for organ health and wellbeing.

 

References

  • Indian Council of Medical Research (ICMR) – Hydration and Kidney Health Studies
  • World Health Organization (WHO) – Water Intake and Health Guidelines
  • National Family Health Survey (NFHS-5) – Nutrition and Lifestyle Data
  • Lancet – Hydration, Cognitive Function and Organ Health Research
  • NITI Aayog – Preventive Healthcare and Lifestyle Recommendations
  • Statista – Global Hydration and Health Trends

See all

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