Health: The Ultimate Treasure

CHAPTER 3: HEALTH: THE ULTIMATE TREASURE

3.1 HEALTH: IS IT MORE THAN NOT FALLING SICK?

Definition of Health According to WHO

**Health** is defined by the World Health Organization as "a state of complete physical, mental, and social well-being, and not merely the absence of disease."

This definition emphasizes that health is much more comprehensive than simply not being sick. A truly healthy person must have:

1. **Physical well-being** — The body functions properly without disease or injury

2. **Mental well-being** — Emotional stability, positive mindset, ability to cope with stress

3. **Social well-being** — Strong relationships, good family connections, ability to adjust with peer groups and society

Components of Health

Health consists of three interconnected aspects shown in Fig. 3.1:

**Physical** — Body strength, immunity, absence of disease

**Mental** — Emotional health, stress management, positive thinking

**Social** — Relationships, family bonds, community connections

What Makes a Person Truly Healthy?

A healthy person:

Can perform various tasks efficiently

Can cope well in different and difficult situations

Can adjust well with peer groups and other members of society

Takes care of their body and mind

Maintains a positive attitude

Enjoys strong social connections

Indian Traditional Knowledge: Ayurveda Approach

According to Ayurveda (ancient Indian medical science):

**True health is a balance of body, mind, and surroundings**

Following **dinacharya** (daily routine) helps maintain balance

Following **ritucharya** (seasonal routine) helps adapt to environmental changes

Eating fresh, wholesome food suited to one's **prakriti** (body constitution) is essential

Regular exercise, cleanliness, restful sleep, and a calm mind support overall well-being

Practices like yoga, meditation, and mindfulness are crucial

Real-Life Example from the Textbook

A Grade 8 student moved to a new school in another city. With no friends and busy parents, he felt lonely and spent excessive time on social media. This caused:

Headaches

Weight loss

Sleep problems

Emotional distress

**Cause-Effect Relationship**: Loneliness and unhealthy habits (excessive screen time) → Physical and mental health problems

**Solution**: Less screen time, counselling, and social support → Improved health

This example shows that health is interconnected — emotional issues led to physical symptoms.

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3.2 HOW CAN WE STAY HEALTHY?

To maintain good health, we must follow several practices related to lifestyle and environment.

3.2.1 Maintaining a Healthy Lifestyle

#### Good Habits to Follow

1. **Balanced Diet**

Eat plenty of fresh fruits and vegetables

Include whole grains in meals

Ensure adequate protein intake

Stay hydrated by drinking water regularly

2. **Physical Activity**

Play outdoors regularly

Walk, run, or cycle daily

Exercise regularly

Practice yoga

Keep yourself active at least 30 minutes per day

3. **Adequate Sleep**

Get 7-8 hours of sleep daily

Helps body and mind rest and recover

Important for growth during teenage years

Maintains concentration and mental health

4. **Stress Management**

Practice yoga or simple breathing exercises like **pranayama**

Spend time with family and friends

Engage in hobbies

Practice meditation and mindfulness

5. **Screen Time Management**

Limit time spent on mobile phones and digital screens

Spend more time in nature and outdoor activities

Avoid screens at least 1-2 hours before bed

#### Bad Habits to Avoid (Fig. 3.2)

1. **Unhealthy Food Choices**

Avoid processed, fatty, or sugary food and drinks

Do not eat fast food daily

Reduce oil and sugar in diet

Skip carbonated and artificially sweetened beverages

2. **Excessive Screen Time**

Can cause dry eye disease in children

Leads to obesity, sleep disorders, and anxiety

Increases loneliness and depression

3. **Harmful Substances**

Say 'NO' to tobacco and smoking

Avoid alcohol and addictive drugs

Prevent addiction from early age

3.2.2 Keep the Environment Clean

#### Environmental Cleanliness and Health

**Clean environment** is essential for good health because:

1. **Air Quality**

Clean air is crucial for respiratory health

Air pollution from vehicles and factories causes problems like coughing and asthma

**Air Quality Index (AQI)** measures how clean the air is

High pollution makes breathing difficult

In Indian cities, vehicular and industrial pollution is a major health hazard

2. **Water Quality**

Safe drinking water reduces water-borne and vector-borne diseases

Contaminated water causes diseases like cholera, typhoid, and dysentery

Boiling water before drinking kills pathogens

3. **Physical Surroundings**

Dirty, unhygienic playgrounds accumulate flies and mosquitos

Proper sanitation reduces disease transmission

Clean homes and schools prevent infection spread

Well-maintained areas promote mental well-being

#### Impact of Unclean Environment

People living in polluted, dirty areas:

Fall sick more frequently

Have higher rates of respiratory diseases

Are at risk from insect-borne diseases

Experience poor physical and mental health

**Real-Life Example**: In Bhadrak district, Odisha, a community sanitation campaign increased toilet construction and usage. This led to:

Significant reduction in open defecation

Fewer cases of diarrhea and infections

Improved child health

3.2.3 Mental and Social Well-being

**Important Fact**: Even if we eat well and live in a clean place, we may not feel good if we are lonely or upset.

Ways to maintain mental and social health:

Spend time with friends and family

Engage in talking and laughing

Participate in group activities and games

Build strong relationships

Seek help when feeling stressed or sad

Practice mindfulness and meditation

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3.3 HOW DO WE KNOW THAT WE ARE UNWELL?

When our body is not working normally, we experience signs and symptoms that indicate illness.

Definition of Symptoms vs. Signs

**Symptom**: What we **feel** inside our body during illness

Example: Pain, tiredness, dizziness, weakness, nausea

**Sign**: Something that can be **seen or measured** by someone else, usually a doctor

Example: Fever (high body temperature), rash, swelling, high blood pressure, bleeding

Common Indicators of Illness

When unwell, our body may show:

1. **Physical Signs**

High body temperature (fever)

Visible rashes or skin changes

Swelling of body parts

Blood in urine or stool

2. **Symptoms Felt**

Pain (headache, abdominal pain, muscle pain)

Tiredness and fatigue

Dizziness or vertigo

Loss of appetite

Nausea or vomiting

3. **Functional Changes**

Inability to concentrate

Loss of sleep

Reduced strength and energy

Difficulty in daily activities

These signs and symptoms help **doctors diagnose** what might be making us unwell and provide appropriate treatment.

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3.4 DISEASES: WHAT ARE THE CAUSES AND TYPES?

Definition of Disease

**Disease** is a condition that affects the normal working of the body or mind. It occurs when one or more organs or organ systems stop functioning properly.

Major Types of Disease

Diseases are classified into two major categories based on their causes and transmission:

#### Type 1: Communicable Diseases (Infectious Diseases)

**Definition**: Diseases caused by **pathogens** that can spread from one person to another.

**What are Pathogens?**

**Pathogens** are disease-causing microorganisms

Types of pathogens:

**Bacteria** — Single-celled organisms (e.g., causes TB, cholera, typhoid)

**Viruses** — Very small organisms that need host cells to reproduce (e.g., causes flu, COVID-19, dengue)

**Fungi** — Multicellular organisms (e.g., causes ringworm, athlete's foot)

**Worms** — Parasitic organisms living in digestive system (e.g., roundworms, tapeworms)

**Protozoa** — Single-celled organisms (e.g., causes malaria)

**Examples of Communicable Diseases**:

Typhoid

Dengue fever

Influenza (Flu)

Chickenpox

COVID-19

Tuberculosis (TB)

Cholera

Measles

#### Type 2: Non-Communicable Diseases (Non-Infectious Diseases)

**Definition**: Diseases **NOT** caused by pathogens and **DO NOT spread** from one person to another.

**Causes**:

Poor nutrition

Unhealthy lifestyle

Genetic factors

Environmental pollution

Lack of physical activity

Excess stress

**Types of Non-Communicable Diseases**:

1. **Chronic Diseases** — Last for more than 3 months

Cancer

Diabetes

Asthma

Heart disease

High blood pressure

2. **Deficiency Diseases** — Caused by lack of specific nutrients

Scurvy (lack of Vitamin C)

Anaemia (lack of iron)

Goitre (lack of iodine)

**Examples of Non-Communicable Diseases**:

Obesity

Diabetes mellitus

Heart disease

Cancer

Asthma

Arthritis

Current Health Scenario in India

**Important Facts**:

Non-communicable diseases (NCDs) like diabetes, heart disease, and cancer have become more common in India

Today, most deaths in India are caused by NCDs, not communicable diseases

India has one of the highest numbers of people with diabetes in the world

More than 100 million people in India are diabetic (ICMR report)

28.6% of Indians are obese

Diabetes and heart attacks are more prevalent in people of South-east Asia according to WHO

**Reason for Increase in NCDs**:

Changes in lifestyle — eating more processed food

Getting less exercise

Increased stress and screen time

Living longer lives

3.4.1 How Are Communicable Diseases Caused and Spread?

All communicable diseases are caused by pathogens that enter the body and cause infection.

#### Routes of Transmission (Methods of Disease Spread) — Fig. 3.4

**1. Through Air (Airborne Transmission)**

When infected person coughs or sneezes, respiratory droplets spread

Diseases: Common cold, influenza, chickenpox, measles, tuberculosis

Prevention: Covering mouth and nose, using masks, maintaining distance

**2. Direct Contact**

Touching an infected person's skin, blood, or body fluids

Shaking hands with infected person

Sharing food or utensils

Diseases: Chickenpox (blisters), common cold

Prevention: Washing hands frequently, avoiding contact with infected person

**3. Indirect Contact**

Touching contaminated surfaces, objects, or personal items of infected person

Using shared towels, handkerchiefs, combs

Touching doorknobs or handles touched by infected person

Diseases: Common cold, influenza

Prevention: Not sharing personal items, disinfecting surfaces

**4. Through Contaminated Food and Water**

Consuming food or water infected with pathogens

Poor sanitation and hygiene

Diseases: Cholera, typhoid, hepatitis A, ascariasis

Prevention: Boiling water, eating properly cooked food, maintaining hygiene

**5. Through Insect Vectors**

**Vectors** are insects that carry and transmit pathogens

Common vectors: Mosquitos, houseflies, ticks

**Mosquitos** spread: Malaria, dengue fever

**Houseflies** spread: Diarrhea, dysentery

Prevention: Using mosquito nets, insect repellents, eliminating breeding grounds

**6. From Animals (Zoonotic Transmission)**

Direct bite from infected animal (e.g., rabies from dog bite)

Contact with infected animal blood or tissues

Diseases: Rabies, bird flu

3.4.2 Communicable Diseases Details — Table 3.1

#### Diseases Spread Through Air

**Common Cold and Influenza**

**Causal Agent**: Virus

**Site of Infection**: Respiratory tract (nose, throat, lungs)

**Symptoms**:

Nasal congestion and discharge

Sore throat

Fever

Cough

Body ache

**Preventive Measures**:

Wash hands frequently with soap and water

Do not share personal items (towels, handkerchiefs)

Cover mouth and nose using a mask

Avoid crowded places when sick

**Chickenpox**

**Causal Agent**: Virus (Varicella-zoster virus)

**Site of Infection**: Respiratory tract initially, then skin

**Symptoms**:

Mild fever

Highly itchy skin

Red rashes

Fluid-filled blisters (vesicles) that rupture and crust over

Rashes appear in waves

**Preventive Measures**:

Complete isolation of infected patient

Cover mouth and nose while coughing/sneezing

Vaccination (varicella vaccine)

Do not share personal items

**Measles**

**Causal Agent**: Virus

**Site of Infection**: Skin and respiratory tract

**Symptoms**:

High fever

Sore throat

Runny nose and cough

Reddish rashes starting from neck, ears, and spreading to other parts

Koplik spots (white spots inside mouth)

**Preventive Measures**:

Isolation of infected patient

Cover mouth and nose

Maintain good personal hygiene

Vaccination (MMR vaccine)

**Tuberculosis (TB)**

**Causal Agent**: Bacteria (*Mycobacterium tuberculosis*)

**Site of Infection**: Lungs (primarily)

**Symptoms**:

Persistent cough lasting more than 2 weeks

Fever, especially in afternoons

Fatigue and general weakness

Loss of appetite

Night sweats

Weight loss

Blood in sputum (in advanced cases)

**Preventive Measures**:

Avoid close contact with TB-infected people

Cover mouth and nose while coughing/sneezing

Maintain good personal and environmental hygiene

Get vaccinated (BCG vaccine)

Ensure proper ventilation and sunlight in homes

#### Diseases Spread Through Contaminated Water and Food

**Hepatitis A**

**Causal Agent**: Virus

**Site of Infection**: Liver

**Symptoms**:

Fatigue and weakness

Fever

Loss of appetite

Nausea and vomiting

Jaundice (yellowing of skin and eyes)

Pain in the upper right abdomen

Dark urine

**Preventive Measures**:

Drink boiled water only

Maintain good sanitation

Practice proper hand hygiene

Vaccination (hepatitis A vaccine)

**Cholera**

**Causal Agent**: Bacteria (*Vibrio cholerae*)

**Site of Infection**: Small intestine

**Symptoms**:

Severe diarrhea (rice-water stools)

Rapid dehydration

Vomiting

Abdominal cramps

Weakness and shock (in severe cases)

**Preventive Measures**:

Maintain personal hygiene and good sanitary habits

Consumption of properly cooked food

Drink boiled or purified water only

Vaccination (oral cholera vaccine)

Proper disposal of sewage

**Typhoid**

**Causal Agent**: Bacteria (*Salmonella typhi*)

**Site of Infection**: Intestine and bloodstream

**Symptoms**:

Headache (severe)

Abdominal discomfort and pain

High fever (sustained, rose-spot rash may appear)

Diarrhea or constipation

Weakness

Loss of appetite

**Preventive Measures**:

Maintain personal hygiene and sanitary habits

Eat properly cooked food

Drink boiled water

Vaccination (typhoid vaccine)

**Ascariasis (Roundworm Infection)**

**Causal Agent**: Parasitic worms (*Ascaris lumbricoides*)

**Site of Infection**: Small intestine

**Symptoms**:

Worms visible in stool (whitish, thread-like)

Loss of appetite

Poor growth and development

Diarrhea

Weight loss

Anaemia (due to nutrient loss)

Abdominal pain

**Preventive Measures**:

Maintain personal hygiene and sanitary habits

Properly cook food

Drink boiled water

Wear shoes/slippers to avoid soil contact

Wash hands before eating

#### Diseases Transmitted by Insects (Vector-Borne)

**Malaria**

**Causal Agent**: Protozoa (*Plasmodium* species)

**Vector**: Female *Anopheles* mosquito

**Site of Infection**: Blood, skin

**Symptoms**:

High fever that comes and goes periodically

Profuse sweating during fever

Chills and body ache

Headache

Weakness and fatigue

**Preventive Measures**:

Use mosquito nets while sleeping (especially in endemic areas)

Use mosquito repellents

Wear long-sleeved clothes, especially during dawn and dusk

Control mosquito breeding by eliminating stagnant water

Keep surroundings clean and dry

**Dengue Fever (Breakbone Fever)**

**Causal Agent**: Virus (Dengue virus)

**Vector**: Female *Aedes* mosquito (active during daytime)

**Site of Infection**: Skin, blood

**Symptoms**:

Sudden high fever

Severe headache (especially behind eyes)

Muscle and joint pain (extreme pain, hence "breakbone" fever)

Nausea and vomiting

Rashes on skin (appears 3-4 days after fever onset)

Weakness and fatigue

**Preventive Measures**:

Use mosquito nets and repellents

Wear long-sleeved clothes

Control mosquito breeding by eliminating still water (flower pots, coolers, buckets)

Keep surroundings clean and dry

Avoid areas with still water

Install screens on windows and doors

Parasites and Parasitic Diseases

**What are Parasites?**

**Parasites** are organisms that live in or on another living being (host) and feed on their nutrients

Examples: Roundworms (Ascaris), tapeworms, hookworms

Usually spread through contaminated food, water, soil, or contact with infected people/animals

Common in areas with poor sanitation

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3.4.2 How Are Non-Communicable Diseases Caused?

Lifestyle-Related Diseases

Non-communicable diseases like cancer, diabetes, and asthma are linked to:

**Lifestyle factors** — How we live and our daily habits

**Diet** — What we eat and drink

**Environment** — Our surroundings and exposure to pollution

**Genetic factors** — Family history and inherited traits

Common Non-Communicable Diseases

**Diabetes Mellitus**

**Definition**: Diabetes is a metabolic disorder where the body cannot properly regulate blood glucose levels, resulting in high blood sugar.

**Causes**:

Combination of hormonal imbalances

Unhealthy eating habits (high sugar, refined carbohydrates)

Lack of physical activity

Being overweight or obese

Family history (genetic predisposition)

Increased stress

**Signs and Symptoms**:

Frequent urination (especially at night)

Excessive thirst and dry mouth

Unexplained weight loss

Persistent tiredness and fatigue

Slow healing of cuts and wounds

Blurred vision

Irritability

**Prevention and Management**:

Maintain a balanced diet with low sugar and refined carbohydrates

Exercise regularly (at least 30 minutes daily)

Maintain healthy body weight

Manage stress through yoga and meditation

Regular health checkups to monitor blood glucose

**Current Scenario in India**:

11.4% of India's population is diabetic

More than 100 million people have diabetes (ICMR report)

Increasingly affecting children and young adults

Major cause of death and disability

**Obesity**

**Definition**: Obesity is a condition where a person has excessive body fat that poses a health risk.

**Causes**:

Consuming more calories than burning

Eating processed and fatty food

Lack of physical activity

Excessive screen time

Unhealthy lifestyle choices

**Signs and Symptoms**:

Excessive body weight

Difficulty in physical activities

Shortness of breath

Joint pain

Related health problems (diabetes, high blood pressure)

**Prevention and Management**:

Eat a balanced diet with proper portions

Engage in regular physical exercise

Reduce screen time

Play outdoor games

Make dietary changes gradually

**Current Scenario in India**:

28.6% of Indians are obese

Rising in children due to sedentary lifestyle and junk food

Major risk factor for diabetes and heart disease

**Heart Disease (Cardiovascular Disease)**

**Definition**: Heart disease includes conditions affecting the heart and blood vessels.

**Causes**:

High blood pressure

High cholesterol levels

Unhealthy diet (high salt, fat, sugar)

Lack of physical activity

Smoking and alcohol

Excessive stress

Obesity

Family history

**Signs and Symptoms**:

Chest pain or discomfort

Shortness of breath

Irregular heartbeat

Weakness and fatigue

Pain in arms, neck, or jaw

**Prevention and Management**:

Maintain a heart-healthy diet (low salt, low saturated fat)

Exercise regularly

Avoid smoking and alcohol

Manage stress through yoga and meditation

Monitor blood pressure and cholesterol

Maintain healthy weight

**Asthma**

**Definition**: Asthma is a chronic respiratory disease where airways become inflamed and narrow, causing breathing difficulties.

**Causes**:

Genetic predisposition (family history)

Environmental allergens (dust, pollen, animal fur)

Air pollution

Cold air

Respiratory infections

Exercise

Emotional stress

**Signs and Symptoms**:

Wheezing (whistling sound while breathing)

Shortness of breath

Chest tightness or pain

Persistent cough (especially at night or during exercise)

Difficulty in physical activities

**Prevention and Management**:

Avoid allergens and irritants

Keep environment clean and dust-free

Use air purifiers

Avoid air pollution

Regular use of prescribed inhalers

Maintain healthy lifestyle

Manage stress

**High Blood Pressure (Hypertension)**

**Definition**: High blood pressure is when the force of blood against artery walls is consistently too high.

**Causes**:

Sedentary lifestyle

High salt diet

Obesity

Stress

Family history

Excessive alcohol and caffeine

Aging

**Signs and Symptoms**:

Often no symptoms (silent disease)

Headaches

Dizziness

Vision problems

Chest pain

**Prevention and Management**:

Reduce salt in diet

Exercise regularly

Manage stress

Maintain healthy weight

Limit alcohol

Regular health checkups

Deficiency Diseases (Non-Communicable)

**Definition**: Deficiency diseases are caused by the lack of specific nutrients in the diet.

**Examples**:

**Scurvy** — Lack of Vitamin C (causes bleeding gums, poor wound healing)

**Anaemia** — Lack of iron (causes weakness, tiredness, pale skin)

**Goitre** — Lack of iodine (causes enlarged thyroid gland)

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3.5 HOW TO PREVENT AND CONTROL DISEASES?

Prevention Principle

**"Prevention is better than cure"** — It is important to protect ourselves from both communicable and non-communicable diseases.

3.5.1 Basic Preventive Measures for Communicable Diseases

#### Hygiene and Sanitation Practices

**Personal Hygiene**:

1. **Handwashing** (Most important)

**Regular handwashing reduces infection by 50%**

Wash hands with soap and water for at least 20 seconds

Wash hands before eating, after using toilet, before preparing food, after playing

Effective against bacteria and viruses

2. **Oral Hygiene**

Brush teeth twice daily

Clean tongue and gums properly

Reduces bacterial growth in mouth

3. **Body Cleanliness**

Bathe regularly with clean water

Keep skin clean and dry

Prevents fungal and bacterial infections

#### Environmental Sanitation

1. **Safe Drinking Water**

Boil water before drinking (kills pathogens)

Use water purification systems

Store water in clean containers

Reduces water-borne diseases like cholera, typhoid, and hepatitis A

2. **Proper Sewage Disposal**

Use toilets for waste disposal

Avoid open defecation

Proper sewage treatment

Prevents contamination of water sources

3. **Food Safety**

Cook food properly at high temperature

Store cooked food in clean containers

Avoid consuming raw or undercooked food

Keep kitchen clean and hygienic

Prevents foodborne infections

#### Behavioral Practices

1. **Covering Mouth and Nose**

Cover mouth and nose with elbow or tissue when coughing/sneezing

Use masks in crowded places

Prevents airborne transmission

2. **Isolation of Sick Persons**

Stay at home when unwell

Avoid contact with others

Helps minimize disease spread

Allows body time to recover

3. **Not Sharing Personal Items**

Do not share towels, handkerchiefs, combs, toothbrushes

Do not share eating utensils or plates

Prevents direct and indirect transmission

4. **Maintaining Distance**

Avoid close contact with sick people

Maintain at least 1-2 meters distance

Reduces respiratory droplet transmission

#### Community-Level Prevention

**Real-Life Example — Bhadrak District, Odisha**:

A community-led sanitation campaign helped build and use toilets

Results:

Significant reduction in open defecation

Fewer cases of diarrhea and infections

Improved overall child health

Created awareness about sanitation

This demonstrates how **community action** can effectively control disease spread.

3.5.2 Immunity and the Immune System

#### Understanding Immunity

**Immunity** is the natural ability of the body to fight against diseases and infections.

**Why do some people get sick more frequently than others?**

Different immune system strength

Nutritional status

Age and overall health

Previous exposure to pathogens

#### The Immune System

**What is the Immune System?**

A special body system that helps fight against diseases

Includes white blood cells, lymph nodes, thymus gland, spleen

Identifies and destroys harmful pathogens

Creates antibodies against specific pathogens

#### Types of Immunity

**1. Natural (Innate) Immunity**

Present from birth

General defense against various pathogens

First line of defense (skin, stomach acid, white blood cells)

**2. Acquired Immunity**

Develops after exposure to a pathogen or disease

Body learns to recognize and fight specific pathogens

Can be obtained through:

Suffering from the disease (active immunity)

Vaccination (artificial active immunity)

Antibodies from mother (passive immunity in infants)

3.5.3 Vaccination and Vaccines

#### What are Vaccines?

**Vaccine** is a biological preparation that teaches the immune system to recognize and fight specific pathogens without causing the disease.

#### How Vaccines Work

1. Vaccine introduces a weakened or harmless form of pathogen to the body

2. Immune system recognizes the pathogen and produces antibodies

3. Body "learns" to fight the pathogen

4. If the actual disease tries to infect later, the immune system quickly defeats it

5. This provides **acquired immunity**

#### Types of Vaccines (Methods of Preparation)

1. **Live Attenuated Vaccines**

Contain weakened (attenuated) pathogens

Can still reproduce but cannot cause disease

Example: Polio vaccine (oral)

2. **Inactivated Vaccines**

Contain dead pathogens

Cannot reproduce or cause disease

Example: Hepatitis A vaccine

3. **Toxoid Vaccines**

Contain inactivated bacterial toxins

Protects against toxins rather than pathogens

Example: Tetanus vaccine

4. **Subunit/Recombinant Vaccines**

Contain only specific harmless parts of pathogen

Safer than whole organism vaccines

5. **mRNA Vaccines (Newer)**

Instruct body cells to produce a harmless part of the pathogen

Immune system then learns to recognize and fight it

Example: Some COVID-19 vaccines

#### Vaccines Given in Childhood (Indian Immunization Program)

Common vaccines administered to children:

**Polio vaccine** — Protects against poliovirus (causes paralysis)

**Measles vaccine** — Protects against measles virus

**Tetanus vaccine** — Protects against tetanus bacteria

**Hepatitis B vaccine** — Protects against hepatitis B virus

**BCG vaccine** — Protects against tuberculosis

**DPT vaccine** — Protects against diphtheria, pertussis (whooping cough), and tetanus

**Chickenpox vaccine** — Protects against varicella virus

#### Real-Life Example: Tetanus Shot After Injury

**Tetanus** is caused by bacteria (*Clostridium tetani*) found in soil.

**Tetanus Vaccine (Toxoid Vaccine)**:

Contains inactivated bacterial toxin (not the bacterium itself)

Safe to administer

Helps immune system develop protection without causing disease

Provides acquired immunity

Administered as primary series in childhood and boosters every 10 years

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3.5.4 HISTORY OF VACCINATION — Edward Jenner and Smallpox

The Smallpox Problem

**Smallpox** was:

One of the deadliest diseases in human history

Caused blisters and severe scarring

Killed millions of people

Had high mortality rate

Feared disease globally

Discovery of the Vaccine

**Edward Jenner (Late 1700s)**:

English physician and scientist

Made a crucial observation

**Observation**:

Milkmaids (people who milked cows) who had **cowpox** never caught **smallpox**

Cowpox was a milder disease that affected cows and could occasionally infect humans

The two viruses are related

**Hypothesis**:

Exposure to cowpox might protect against smallpox

**Experimentation**:

In 1796, Jenner tested his hypothesis

He infected a boy with cowpox material from an infected milkmaid

The boy developed mild cowpox

Later, Jenner exposed the same boy to smallpox material

The boy did NOT get smallpox

**Results**:

People infected with cowpox sap became resistant to smallpox

Jenner had discovered the first vaccine

Named it "vaccination" from Latin "vacca" (cow)

**Application**:

Mass vaccination against smallpox began

Gradually spread across the world

Eventually helped **eradicate (completely eliminate) smallpox worldwide**

Last case of smallpox reported in 1977

Smallpox is now completely extinct in nature

Importance of Jenner's Discovery

Introduced the concept of vaccination

Demonstrated prevention through immunity

Led to development of vaccines for other diseases

Saved millions of lives

Revolutionized public health

Indian Traditional Knowledge — Variolation

**Before Modern Vaccines**, India had a traditional method:

**Variolation**:

Traditional method to protect against smallpox

Involved using material from smallpox sores

Practitioners would scratch the skin and introduce material