Call
+918447748545

Published on: Jul 22, 2020
2 minute read
By: Dr Rajan Choudhary

The Oxford Vaccine

Recently we wrote a blog on the success of an RNA vaccine against SARS-CoV-2, the virus responsible for COVID-19. Within just a few weeks of that incredible research breakthrough, researchers at Oxford University’s Jenner Institute have announced a COVID vaccine that has induced remarkable immune response against the virus.

This study was published in the Lancet, one of the most prestigious medical journals in the world, and a simple summary suggests the vaccine has no early safety concern and is able to induce a strong immune response with both T cells and B cell/antibodies.

THE VACCINE

ChAdOx1 nCoV-19, now known as AZD1222, was co-developed by the University of Oxford and one of its spin-off companies, Vaccitech. The vaccine uses a viral vector based on a common cold virus (adenovirus). This carries genetic material for the SARS-CoV-2 spike protein. In our previous blog, we saw how the spike proteins are used by the virus to target and fuse with our target cells, allowing the virus to invade, replicate and ultimately cause the disease known as COVID. It is also a good target for the human immune system to recognize and attack.

The viral vector delivers the genetic material inside our cells. The spike protein is then produced by our cells, recognized by the immune system as a viral target, and an immune response is created against it. This can be antibodies, which recognize, attach to and mark the virus in our blood, allowing for other white blood cells to destroy the virus.

In this case, the vaccine also produced a T cell response. T cells can recognize cells infected by a virus-based on the markers present on the surface of infected cells. They can tell an infected cell to destroy itself, thereby destroying the virus within without spreading the infection. They also have other functions that we will not discuss in this blog.

THE STUDY

This study was a Phase I/II trial that started in April using the vaccine named ChAdOx1 nCoV-19. This vaccine development started in January 2020, and progress on development has been incredibly rapid. Whilst our previous study had just 45 people, this study looked reviewed over 1,000 healthy adults. 10 of these participants received two doses of the vaccine.

In a study the more participants there are, the greater the power of the study. If the vaccine has any side effects, even ones that rarely occur, it is more likely to be picked up in studies with more people. Similarly having more people helps show that the vaccine is effective, and the strong responses are not merely a fluke or accident. Another benefit of this study is it was able to compare the vaccine against a control group. This shows the results were not simply a placebo and allowed comparison of side effects as well.

The majority of side effects were feeling feverish, chills, muscle ache, headache, and malaise, all symptoms treatable with paracetamol. None of the participants had any serious side effects. It took just 14 days to create a T cell response, and 28 days to make strong antibodies. In 91% of patients, this was enough to neutralize the COVID coronavirus. Receiving two doses gave an even stronger antibody response, and all participants were able to stop the virus.

WHAT NEXT

The news from the University of Oxford is needed, as infection rate and mortality continue to increase in countries such as the US and Brazil. The ability to induce an antibody response without causing harm to the patient shows we have made huge progress in the fight against COVID-19. Further Large scale Phase III trials been set up through a global partnership, and include studies in the US with over 30,000 patients, studies in children as well as some in low to middle-income countries.

If successful a vaccine would be essential in preventing a second wave of COVID in the winter when the elderly population is most at risk. And it would be the key to restarting the economy and getting our everyday lives back to where it was pre-pandemic.

Read Blog

Health Problems Linked to Excessive Caffeine Intake: When Too Much Becomes Harmful

Caffeine is one of the most widely consumed stimulants in the world. Found in coffee, tea, energy drinks and many soft drinks, it is often used to improve alertness and combat fatigue. While moderate caffeine consumption can be safe for most people, understanding the health problems linked to excessive caffeine intake is important, especially as daily consumption levels continue to rise in India.

Urban lifestyles, long working hours and increased reliance on energy drinks have made caffeine overconsumption a growing public health concern.

How Caffeine Works in the Body

Caffeine stimulates the central nervous system by blocking adenosine, a chemical responsible for promoting sleep and relaxation.

This results in:

increased alertness
faster heart rate
heightened mental activity

However, overstimulation places stress on multiple body systems.

What Is Considered Excessive Caffeine Intake?

According to WHO and global health guidelines:

up to 400 mg per day is considered safe for most healthy adults

Excessive intake occurs when:

multiple caffeinated beverages are consumed daily
energy drinks are used frequently
caffeine is consumed late in the day

Many people unknowingly exceed safe limits.

Nervous System Overstimulation

Excess caffeine overstimulates the brain.

Common symptoms include:

restlessness
nervousness
tremors
irritability

Chronic overstimulation can worsen stress and reduce emotional stability.

Anxiety and Panic Symptoms

Caffeine increases adrenaline release.

This can:

trigger anxiety attacks
worsen panic disorder
increase feelings of unease

ICMR mental health studies note caffeine as a common trigger for anxiety symptoms in sensitive individuals.

Sleep Disruption and Insomnia

Sleep is one of the first systems affected.

Excessive caffeine:

delays sleep onset
reduces deep sleep
shortens total sleep duration

Even caffeine consumed 6–8 hours before bedtime can impair sleep quality.

Impact on Heart Health

High caffeine intake affects the cardiovascular system.

Possible effects include:

increased heart rate
palpitations
irregular heart rhythm

People with underlying heart conditions are particularly vulnerable.

Blood Pressure Elevation

Caffeine temporarily raises blood pressure.

Chronic excessive intake may:

worsen hypertension
increase cardiovascular risk

NFHS-5 data highlights rising hypertension prevalence in India, making caffeine moderation important.

Digestive System Problems

Caffeine stimulates stomach acid production.

This can cause:

acidity
heartburn
gastritis
bloating

People with sensitive digestion may experience symptoms even at lower doses.

Dependency and Withdrawal Symptoms

Regular high intake leads to caffeine dependence.

Withdrawal symptoms include:

headaches
fatigue
irritability
difficulty concentrating

Dependence reinforces overconsumption cycles.

Effect on Bone Health

Excessive caffeine:

increases calcium loss through urine
may affect bone density over time

This is particularly concerning for older adults and women.

Dehydration and Electrolyte Imbalance

Caffeine has a mild diuretic effect.

High intake without adequate hydration may lead to:

dehydration
muscle cramps
fatigue

Hot climates increase this risk.

Impact on Blood Sugar and Metabolism

Caffeine affects glucose metabolism.

Excessive intake:

worsens insulin sensitivity
increases stress hormone release

This may increase diabetes risk when combined with poor lifestyle habits.

Energy Drinks and Hidden Risks

Energy drinks often contain:

very high caffeine levels
added sugar
stimulants

Lancet reports associate energy drink overuse with heart rhythm disturbances and metabolic stress.

High-Risk Groups

Certain individuals should be especially cautious:

people with anxiety disorders
those with heart disease
pregnant women
individuals with sleep disorders

Safe limits may be lower for these groups.

Signs You May Be Consuming Too Much Caffeine

Warning signs include:

frequent palpitations
chronic insomnia
persistent anxiety
digestive discomfort
reliance on caffeine to function

These signals indicate the need for reduction.

How to Reduce Caffeine Intake Safely

Effective strategies include:

gradual reduction rather than abrupt stopping
switching to decaffeinated options
avoiding caffeine after mid-afternoon
improving sleep and nutrition

Small steps prevent withdrawal symptoms.

Healthier Alternatives for Energy

Better ways to improve energy include:

adequate sleep
balanced meals
hydration
regular physical activity

These support sustained energy without overstimulation.

Role of Preventive Health Awareness

Preventive healthcare focuses on:

identifying lifestyle triggers
reducing dependency habits

NITI Aayog highlights lifestyle modification as key to non-communicable disease prevention.

Long-Term Health Consequences of Ignoring Excess Intake

Chronic caffeine overuse increases risk of:

sleep disorders
anxiety and mood issues
heart rhythm problems
digestive disorders

These conditions often develop gradually.

Conclusion

The health problems linked to excessive caffeine intake extend beyond temporary jitters or sleep loss. Chronic overconsumption strains the nervous system, disrupts sleep, affects heart rhythm, worsens anxiety and impacts digestion and metabolism. While caffeine can be enjoyed safely in moderation, recognising personal limits and maintaining balance is essential for long-term health. Listening to early warning signs and adopting healthier energy habits can prevent serious health consequences.

References

World Health Organization (WHO) – Caffeine Intake and Health Guidelines
Indian Council of Medical Research (ICMR) – Nutrition and Mental Health Studies
National Family Health Survey (NFHS-5) – Hypertension and Lifestyle Risk Data
Lancet – Energy Drinks, Caffeine and Cardiovascular Effects
NITI Aayog – Preventive Health and Lifestyle Modification Reports
Statista – Caffeine Consumption Trends in India

Request A Callback

+91

By using this website/app, I confirm that I am at least 18 years old and consent to the processing of my personal data in accordance with the Terms of Service, Privacy Policy, and Declaration.