• 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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Excessive

Heat Exhaustion Warning Signs: Symptoms You Should Never Ignore

Heat-related illnesses are common during hot weather, particularly in tropical countries like India where summer temperatures can become extreme. Heat exhaustion is a serious condition that occurs when the body overheats due to prolonged exposure to high temperatures and inadequate hydration.

Recognizing heat exhaustion warning signs early can prevent life-threatening complications such as heatstroke.

 

What Is Heat Exhaustion?

Heat exhaustion is a heat-related illness caused by:

  • Excessive heat exposure
     

  • Dehydration
     

  • Loss of electrolytes through sweating
     

It often occurs during outdoor work, exercise or travel in hot environments.

If untreated, it may progress to heatstroke — a medical emergency.

 

Common Heat Exhaustion Warning Signs

1. Heavy Sweating

Excessive sweating is one of the earliest signs.

The body attempts to cool itself through perspiration, leading to fluid loss.

2. Dizziness or Lightheadedness

Low blood pressure due to dehydration may cause:

  • Feeling faint
     

  • Blurred vision
     

  • Weakness
     

 

3. Fatigue and Weakness

Muscle weakness and exhaustion occur as the body struggles to regulate temperature.

 

4. Nausea and Vomiting

Digestive discomfort is common in heat-related illnesses.

 

5. Headache

Dehydration and heat stress can trigger throbbing headaches.

 

6. Muscle Cramps

Electrolyte imbalance may cause painful muscle cramps, especially in legs.

 

7. Rapid Heartbeat

Increased heart rate helps circulate blood for cooling but may indicate strain.

 

8. Cool, Clammy Skin

Despite hot weather, skin may feel cool and moist due to heavy sweating.

 

Who Is at Higher Risk?

Certain groups are more vulnerable:

  • Outdoor laborers
     

  • Athletes
     

  • Elderly individuals
     

  • Children
     

  • People with chronic illnesses
     

  • Individuals on certain medications
     

Urban heat exposure increases risk during peak summer months in India.

 

Heat Exhaustion vs Heatstroke

Heat exhaustion is serious but manageable if treated promptly.

Heatstroke symptoms include:

  • High body temperature (above 40°C)
     

  • Confusion or disorientation
     

  • Dry, hot skin
     

  • Seizures
     

  • Loss of consciousness
     

Heatstroke requires immediate emergency medical attention.

 

Immediate Steps to Take

If heat exhaustion is suspected:

  1. Move to a cool, shaded area
     

  2. Loosen tight clothing
     

  3. Drink water or oral rehydration solution
     

  4. Apply cool cloths to body
     

  5. Rest until symptoms improve
     

Seek medical care if symptoms persist beyond one hour.

 

Prevention Tips

Stay Hydrated

Drink water regularly, even if not thirsty.

 

Avoid Peak Sun Hours

Limit outdoor activity between 12 PM and 4 PM.

 

Wear Light Clothing

Choose loose, breathable fabrics.

 

Use Sun Protection

Wear hats and sunglasses when outdoors.

 

Take Frequent Breaks

Rest in shaded or air-conditioned areas.

 

Maintain Electrolyte Balance

Use oral rehydration solutions if sweating heavily.

 

Heat Illness in the Indian Context

India frequently experiences heatwaves, especially in northern and central regions. Public awareness about hydration and heat safety is essential to reduce hospitalizations and fatalities.

Community-level education can significantly improve prevention.

 

When to Seek Medical Help

Immediate medical attention is required if:

  • Symptoms worsen
     

  • Body temperature rises significantly
     

  • Confusion develops
     

  • Fainting occurs
     

  • Vomiting persists
     

Early treatment prevents severe complications.

 

Conclusion

Heat exhaustion is a preventable but potentially dangerous condition. Recognizing warning signs such as heavy sweating, dizziness, nausea and muscle cramps allows timely intervention.

With rising summer temperatures, especially in India, proactive hydration and heat safety measures are essential. Preventive care and awareness can protect vulnerable individuals and reduce health risks.

Staying cool and hydrated is the simplest way to safeguard your health during hot weather.

 

References

  • Indian Meteorological Department – Heatwave Reports

  • World Health Organization – Heat-Related Illness Guidelines

  • Indian Council of Medical Research – Public Health Advisory

  • National Disaster Management Authority (India) – Heatwave Action Plan

  • Lancet Planetary Health – Climate and Health Research

 

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