• Published on: Apr 04, 2020
  • 3 minute read
  • By: Dr Rajan Choudhary

Developing A Vaccine For COVID-19? Part 1

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It is often stated vaccination has made the greatest contribution to global health of any human discovery, other than clean water and sanitation, and their impact on everyday life is immediately evident. We have managed to completely eradicate two major infections from existence (smallpox and rinderpest) , and the WHO are working towards adding polio to that list.

In these cases the numbers speak for themselves. It is estimated that the eradication of smallpox in 1980 has saved 5 million lives per year, adding up to 150 to 200 million by 2018. Common vaccination programmes for polio, measles, mumps, rubella, rabies and hepatitis A have prevented nearly 200 million cases from occurring in the US alone over the past 50 years, and 4.5 billion instances of the diseases worldwide.

We have achieved a 99% immunisation rate against polio, preventing children from suffering crippling paralysis, and only 3 countries remain. Sadly, around 1.4 million children under 5 still die from preventable diseases each year as they do not have access to these life saving vaccines, but charities and public health organisations around the world are working hard to improve access.

So what are vaccines? And how will they help is in the face of the latest pandemic? Here we will go into the challenges behind making vaccines, and why a vaccine against COVID-19 is unlikely to be ready in the next few months, or even this year.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4024226/ contribution of vaccination

https://www.who.int/features/factfiles/polio/en/ polio eradication

https://www.sciencedaily.com/releases/2017/03/170303163208.htm study article

WHAT IS A VACCINE

The human body’s immune system is incredibly smart. It is able to distinguish between infective organisms, such as bacteria, viruses and parasites, from our own body’s cells, target these invaders for destruction and keep our bodies healthy. Even better, the body remembers any previous infections it has had before, recognise these previous infections even quicker and even eradicate the disease before we know we are infected.

Vaccines target the immune system’s memory by presenting them with pieces of these infective diseases. The small amounts do not cause any infective symptoms, but if the person is infected later in life their body will mount a quicker response and prevent them from falling ill. These vaccines can contain broken up parts of the organisms, “dead” organisms or “live” versions that have been severely weakened so they cannot cause any harm.

In summary, medicines treat us when we get an infection. Vaccines make sure we never suffer from an infection in the first place.

https://www.chop.edu/centers-programs/vaccine-education-center/making-vaccines/how-are-vaccines-made Making Vaccines

THE HURDLES WE FACE IN RESEARCH

Making a vaccine is a difficult process, one that can take 3–5 years and cost hundreds of millions of dollars, sometimes billions of dollars. This is because there are many difficult steps to be taken in the process of creating a vaccine that is effective, but more importantly one that is safe.

To start with the troubling organism has to be identified. For COVID-19 it took a few weeks to recognise the virus responsible, and some time more to understand its genetic code and grow the virus in lab conditions. We then have to understand the virus, how it infects, how it causes symptoms, and how it has mutated compared to the coronaviruses responsible for SARS and MERS.

After this, we have to isolate parts of the virus our immune system will recognise. This is usually the outside coat of the virus. The DNA responsible for making these parts need to be found in the virus’ genetic code, and put inside other “skeleton” viruses. This will force the dummy virus to look like coronavirus, without the ability to infect and kill someone.

These dummy viruses can be injected into animals to see if it causes an immune reaction, whether the immune system recognises it as the coronavirus responsible for COVID-19, and whether it will protect the animal from the real COVID-19. Up to now the research has likely cost a few million dollars. The next step is when the price inflates up to billions.

If the vaccine appears safe in animals, it can be tested in humans. This can be dangerous at first, since we don’t know whether a vaccine that works in an animal will work in a human. And we don’t know if there will be any side effects to the vaccine. Human testing has to be very thorough, very careful, and safe for use. If you give too much of the virus it might make the person sick, too little and it wont immunise the person. These clinical trials can take years, and if the vaccine fails at this point its back to the drawing board, to try another step.

https://www.theatlantic.com/politics/archive/2014/10/how-to-make-an-ebola-vaccine-5-simplified-steps/454443/ ebola vaccine

Now we have a basic understanding of what vaccines are and why it takes so long to make a vaccine. In the next part we will look at why viral vaccines can cause even more problems, and how far we have come with the COVID-19 vaccine,

Dr Rajan Choudhary, London UK

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Air pollution

Impact of Air Pollution on Human Health: Risks, Effects and Prevention

Air pollution has become one of the most serious public health challenges worldwide. In India, rapid urbanisation, vehicle emissions, industrial activity and seasonal factors contribute to high pollution levels, especially in metropolitan cities. Understanding the impact of air pollution on human health is essential because exposure to polluted air significantly increases the risk of chronic illness and premature death.

According to the World Health Organization, air pollution is responsible for millions of premature deaths globally each year. Studies published in The Lancet highlight India as one of the countries most affected by air quality-related health burdens.

 

What Is Air Pollution?

Air pollution occurs when harmful substances such as:

  • particulate matter (PM2.5 and PM10)

  • nitrogen dioxide

  • sulfur dioxide

  • ozone

  • carbon monoxide

accumulate in the atmosphere at unsafe levels.

Among these, PM2.5 particles are particularly dangerous because they are small enough to penetrate deep into the lungs and bloodstream.

 

Respiratory Health Effects

The most immediate and visible impact of air pollution is on the lungs.

Short-Term Effects

  • coughing

  • throat irritation

  • wheezing

  • shortness of breath

Long-Term Effects

  • chronic bronchitis

  • asthma worsening

  • reduced lung capacity

  • chronic obstructive pulmonary disease (COPD)

Children and elderly individuals are especially vulnerable.

 

Impact on Heart Health

Air pollution does not only affect the lungs. Fine particles enter the bloodstream and trigger inflammation.

Long-term exposure increases risk of:

  • hypertension

  • heart attack

  • stroke

  • atherosclerosis

ICMR reports show cardiovascular diseases remain a leading cause of mortality in India, with pollution being a significant contributing factor.

 

Impact on Immune System

Constant exposure to polluted air weakens the immune response.

This leads to:

  • frequent respiratory infections

  • slower recovery from illness

  • increased susceptibility to viral diseases

Pollution also increases systemic inflammation.

 

Effect on Children’s Health

Children are particularly vulnerable because:

  • their lungs are still developing

  • they breathe more air relative to body weight

  • they spend time outdoors

Long-term exposure may reduce lung growth and increase asthma risk.

 

Impact on Pregnant Women and Infants

Research published in Lancet indicates that high pollution exposure during pregnancy increases risk of:

  • low birth weight

  • premature birth

  • developmental complications

Protecting pregnant women from pollution exposure is critical.

 

Air Pollution and Cancer Risk

Prolonged exposure to air pollution increases the risk of lung cancer.

WHO classifies outdoor air pollution as a carcinogen.

 

Mental Health and Cognitive Impact

Emerging research suggests pollution may contribute to:

  • cognitive decline

  • mood disorders

  • reduced concentration

Clean air supports brain health.

 

Seasonal Pollution in India

During winter months, many cities experience severe smog due to:

  • crop burning

  • temperature inversion

  • increased emissions

Monitoring Air Quality Index (AQI) helps individuals take precautions.

 

Signs of Pollution-Related Health Impact

  • persistent cough

  • chest tightness

  • eye irritation

  • unusual fatigue

  • worsening asthma

Individuals experiencing these symptoms should consult healthcare providers.

 

Preventive Measures to Reduce Exposure

Monitor AQI

Avoid outdoor activities during high pollution days.

 

Use Protective Masks

N95 masks filter fine particles effectively.

 

Indoor Air Quality

Use air purifiers and keep windows closed during peak pollution.

 

Avoid High-Traffic Areas

Limit time near busy roads.

 

Maintain Healthy Lifestyle

Strong immunity helps reduce pollution-related health risks.

 

Role of Preventive Healthcare

Regular screening for:

  • lung function

  • blood pressure

  • heart health

helps detect early damage caused by pollution.

Urban populations should prioritise routine health checkups.

 

Long-Term Public Health Impact

Air pollution contributes significantly to:

  • healthcare burden

  • productivity loss

  • economic strain

Preventive awareness and environmental policies are essential.

 

Conclusion

The impact of air pollution on human health is profound and far-reaching. From respiratory disorders and heart disease to immune suppression and increased cancer risk, polluted air affects nearly every organ system. In India’s urban environment, proactive measures such as monitoring AQI, using protective masks and maintaining regular health screenings are crucial. Protecting oneself from air pollution is not just about comfort—it is a vital step in preserving long-term health and preventing chronic disease.

 

References

  • World Health Organization (WHO) – Air Pollution and Health Reports
  • Indian Council of Medical Research (ICMR) – Environmental Health Studies
  • National Family Health Survey (NFHS-5) – Respiratory and Cardiovascular Data
  • NITI Aayog – Environmental and Preventive Health Strategy Reports
  • Lancet – Global Burden of Disease and Air Pollution Research

See all

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