Vaccines child

Overview of vaccines

Numerous diseases can impact health and lifestyle at any point in time during an individual’s life. Few of them are contagious, few are fatal and few are resistible. Irrespective of the nature of the disease, the human body should have the capacity, more precisely the immune capacity to combat the pathogens or causative agents triggering these diseases. This necessitates adequate immunization in childhood through the injection of vaccines. But before that, a proper knowledge of the required vaccinations and possible reactions is necessary so as to determine the types of immunizations a child can sustain. Unfortunately, in many countries, the knowledge related to immunizations is lacking and this has resulted in 19.4 million immunocompromised infants worldwide in the year 2015.


What are vaccines?

VaccinesVaccines are medically defined as antigenic agents synthesized from the causative agent of a disease (or any other artificial substitute of the same) which are essential for building body immunity against several diseases. There are specific vaccines for different diseases and each of them has a significant role in building the body’s immune capacity. Vaccines are also known to be used to treat certain diseases (therapeutic vaccines). Vaccines are normally delivered in liquid form via injections, or via oral or intranasal paths. Vaccines are usually synthesized from whole microorganisms or specific components of microorganisms and provide protection against that particular pathogen (viral or bacterial) in future.


What are the properties of vaccines?

Two primary factors determine the disease-preventing ability of a vaccine. These are-

  • Effectiveness and durability of the administered vaccine
  • Vaccination coverage in a given population

Vaccines adultTwo important properties that determine the utility of vaccines are –

  • Vaccine effectiveness– It is defined as the performance of a particular vaccine under varying field conditions. Vaccine effectiveness strongly depends on the performance of vaccine delivery programs. It basically measures the ability of a vaccine to prevent the detrimental effects of a certain disease (such as hospitalization or death).
  • Vaccine efficacy– It is defined as the performance of a particular vaccine under specific study conditions (prospective approach). Vaccine efficacy measures the extent of prevention of a disease.

Apart from the ones discussed above, all vaccines should have the following essential properties-

  • Ability to provide long-lasting immunity
  • Ability to provide both humoral (extracellular) and cellular immunity
  • Should not trigger autoimmune effects or hypersensitivity
  • Should have a reasonable cost of production
  • Can be stored and delivered under normal environmental conditions
  • Should be safe to use


Types of immunizations

Immunizations are broadly classified into two categories. These are described below-

  • Active immunization: It is the type of immunization acquired via past occurrence of a particular disease. Individuals surviving the disease (caused by a specific pathogen) are less susceptible to the same disease in future. Active immunization involves the production of antibodies (humoral or cellular) in response to a specific antigen. Vaccines can induce active immunization by creating immunological memory (generate immune response similar to that evoked by a natural disease). It is usually long lasting in nature.
  • Passive immunization: It is the type of immunization in which antibodies are passed on to one person from another, such as from mother to fetus. This type of immunization is temporary in nature and cannot provide protection after the progressive degradation of antibodies. Transplacental immunization is the most common example of this type.


The working mechanism of vaccines

Vaccines childWhen vaccines are injected into the body in the form of inactivated or weakened pathogens, an immune response is triggered, which is similar to the body’s natural response to an infection.

The only difference is that in case of artificially injected pathogens, possibilities of occurrence of the disease is nil since the pathogens are in benign condition and do not have the capacity to cause infections.

The disease-causing pathogens are called “antigens” and the substances produced by the body in response to these antigens are called “antibodies”.

The antibodies combine with the antigens and destroy them through the mediation of the immune cells of the body (T lymphocytes). The artificially induced immune response creates immunological memory (both humoral and cellular) within the body and helps the body identify and destroy similar infectious pathogens in the future. In this way, diseases are prevented effectively.


Different types of vaccines

Vaccines are classified into different categories depending on the source of derivation and composition. These are discussed below-

Live attenuated vaccines

These vaccines are extracted from disease-causing bacteria or virus. These pathogens are attenuated and inactivated in the laboratory through repeated testing and culturing. Multiplication of the attenuated pathogens (in the form of vaccines) occurs within the body of the vaccinated person for a considerable period of time, which in turn triggers an immune response. These vaccines are usually provided in low dosage and do not cause disease within the body. In few rare cases, they might induce infections of very mild nature since these pathogens are almost benign in nature.

 What are the advantages? 

  • The injected microbes can help generate immunological memory similar to the one induced by natural disease.
  • Only a very small dosage is required since these microbes replicate within the body.
  • One time administration is enough for long-lasting immunity. Multiple booster doses are unnecessary.
  • Administration of whole microbes can cause protection against few other kinds of infections as well.
  • Few vaccines of this category can be delivered orally and can provide effective protection against the pathogen at the site of infection itself (Eg: vaccines for mucosal immunity and IgA synthesis). These oral vaccines are much cheaper.
  • These vaccines can help regulate epidemics.

What are the disadvantages?

  • In few rare cases, these supposedly benign vaccines may transform into virulent forms and cause severe infections.
  • Live attenuated vaccines cannot be provided to individuals having very weak immunity since they can cause serious illnesses and even death.
  • Optimum storage conditions are required since these microbes need to be in a condition to replicate after administration into the individual’s body.
  • Intervention by circulating antibodies in the body may impede the development of active immunity due to poor immune response.
  • These microbes are easily degradable and are extremely thermosensitive and photosensitive.

Inactivated vaccines

These vaccines are produced via bacterial and viral culturing in the laboratories and are then inactivated by heat or chemicals (mostly formalin). For synthesizing fractional vaccines, the inactivated microbes are further cultured and treated to extract only those components of the pathogen essential for vaccine preparation. A common example of this type is the polysaccharide capsule of Pneumococcus, In this case, chances of infection after administration of the vaccines are nil (even in an immunosuppressed individual) since the microbes are dead and cannot multiply within the body. A full dosage of the vaccine is administered at the same time. Two to three booster doses are required in this case for full protection against the disease. Examples of inactivated whole virus vaccines are- Influenza, Polio, Rabies and Hepatitis A. Examples of inactivated whole bacterial vaccines are- Pertussis, Typhoid, Cholera, and Plague.

 What are the advantages?

  • It is very safe to use and can be administered to immunosuppressed individuals and pregnant women
  • They are cheaper than attenuated vaccines
  • Optimum storage conditions are not required since the microbes are inactivated
  • They are not disturbed by circulating antibodies

What are the disadvantages?

  • A full dose of the vaccine has to be injected since the pathogens do not replicate within the body
  • A single dose only provides primary immunity. But for full immunity, multiple booster doses are needed
  • It is not very effective for generating cellular immunity
  • Few vaccines of this class can trigger adverse reactions after injection (Eg: encephalomyelitis induced by Bordetella pertussis)

Subunit vaccines 

Subunit vaccines are prepared from fractional components of the microorganism instead of the entire microbe. This is done in order to extract those antigens that provide protective immunity. Subunit vaccines are mainly made up of toxoids, subcellular components, and surface antigens. The performance of subunit vaccines is enhanced by administering them with adjuvants. They facilitate sustained immune stimulation.

 What are the advantages?

  • These vaccines can be safely administered to immunodeficient people
  • They normally do not produce side effects

What are the disadvantages?

  • These vaccines are less effective in terms of antigenicity. For example, peptide segments do not produce the same immune effect as that of the entire organism.
  • Some of the peptides are closely linked to the Human Leukocyte Antigen (HLA) and hence cannot provide complete immunity against all kinds of diseases.

Polysaccharide vaccines

These are a category of subunit vaccines made up of sugar molecule chains and are often found on the surface capsules of few bacteria. Immune response triggered by polysaccharide vaccines are usually T-cell independent. These vaccines are not very effective in immunodeficient people especially in infants (since they have immature immune systems). Performance of polysaccharide vaccines induced antibody is less than that induced by protein antigens because, in the former, very less IgG is produced. Examples of Polysaccharide vaccines are Pneumococcal, Meningococcal and Salmonella typhi.

Conjugate vaccines

These are primarily synthesized from capsulated bacteria and eliminate the problems related to polysaccharide vaccines. The conjugated bonds transform the immune response from T-cell independent to T-cell dependent. This enhances immunogenicity in infants. But one major disadvantage is that the extracted capsulated antigen acts as subunit vaccine and can enhance only humoral (extracellular) immunity. Also, multiple booster doses are required to induce complete immunity.

Recombinant vaccines

The vaccines produced by means of recombinant DNA technology or genetic engineering are called recombinant vaccines. The different means of preparation of this kind of vaccines are-

  • Use of engineered vector (Eg: Vaccinia virus)
  • Introducing mutation by deleting a portion of DNA
  • Reassortment of genomes of virulent and avirulent variants
  • Edible vaccines produced via introducing genetic coding for significant antigens in plants

What are the advantages?

  • These vaccines can be safely administered and are easy to store
  • Antigen segments having adverse effects can be safely removed from the main vaccine. Eg: Cholera toxin A can be safely eliminated from cholera vaccine

 What are the disadvantages?

  • Cost of production is high since the synthesizing process involves relocation, cloning, and expression of the antigen in the new vector
  • It generates adverse reactions in immunodeficient people

DNA vaccines

These types of vaccines are still in the research stage. In this case, the required antigens are located and cloned. The DNA is injected into the muscle cells of the vaccine recipient. They can also be introduced via the intranasal path. DNA vaccines provide both humoral and cellular immunity.

 What are the advantages? 

  • Transport and storage of DNA vaccines are very easy since the DNA molecules are very stable and are resistant to light and temperature
  • The DNA sequence can be changed anytime in the laboratory as per requirements
  • The injected DNA does not replicate and only the necessary proteins are encoded
  • Due to the absence of a protein component, no immune response is created against the inserted vaccine

What are the disadvantages?

  • Insertional mutagenesis may result from insertion of DNA into the host genome
  • Anti-DNA antibodies may be generated in response to introduced DNA


The dosage of common vaccines

Dosage recommendations of few common vaccines are listed below-


What are the adverse effects of vaccinations?

Infants having severe allergic reactions to vaccines should be immunized only after proper consultation with a pediatrician. In general, the following reactions are observed after immunization-


Benefits of vaccination

  • Vaccinations are administered to children to ensure that they do not end up with serious health conditions such as meningitis, measles etc.
  • Vaccinations help in ensuring that children don’t develop or acquire disabling or life-threatening malaises and infections.

Side effects of vaccinations

  • Fever
  • Headache
  • Fatigue
  • Joint or body pain
  • Shivering
  • Soreness or redness at the injection site.



  • A British scientist, Edward Jenner, developed the first smallpox vaccination in 1796.
  • 2-3 million deaths are prevented each year due to vaccines.
  • Vaccines are not always administered in the form of shots; they can be given orally as well.


  • In the late 18th century, King Charles IV of Spain wanted to spread the smallpox vaccination. He used 22 orphan boys who were vaccinated and their blood was used to make the vaccination


  • Since its introduction in 1998, the vaccination against bacterial meningitis has brought down the incidence rate of the disease by 99%.

Related Conditions

Want to live a healthy lifestyle?

Subscribe to free FactDr newsletters.


If you're enjoying our website, we promise you'll absolutely love our new posts. Be the first one to get a copy!

Get factually correct, actionable tips delivered straight to your inbox once a week.

I want the latest scoop on :

We hate spam too. We will never share your email address with anyone. If you change your mind later, you can unsubscribe with just one click

By clicking Subscribe, I agree to the FactDr Terms & Conditions & Privacy Policy and understand that I may opt out of FactDr subscriptions at any time.


Dos and Don'ts

  • Get a flu vaccination every year to help prevent the flu.
  • Take the patient to the hospital in case there are any abnormal reactions posts the vaccination.
  • Maintain a healthy diet of whole-grains before getting a vaccination shot.
  • Vaccinate an infant if they are sick as their immune system would be weak. Doing so can make the pathogens enter the central nervous system and cause life-threatening damages.
  • Get your child vaccinated again with the same vaccines if your child had a reaction to it the first time. Doing so could lead to severe reactions




Related Conditions

Trending Topics

anal sex
Anal sex: Tips from experts on how to be kinky yet safe Whether it irks you or stokes your fantasies, anal sex has always been an intriguing sexual act. Learn…
hidden benefits walking
9 benefits of walking we bet you didn’t know! Did you know walking can be the miracle pill for eternal youth? Everyone knows walking is good for…
understanding addiction
Addiction explained: An obsession that could cost you your life Is addiction a behavioral disorder? Or is it a chronic disease? How does addiction cause chemical and structural…
Jicama: A fiber-rich tuber for your weight loss goals Pronouced as HEE-kah-ma, Jicama is the "new kid on the block" that has taken the world by the…
eating disorder anorexia
Eating Disorders: Lifestyle choice or a psychological condition? Is eating disorder just a harmless bad habit? Or does it represent grim psychological disorders? Do you want…
yoga health benefits
How to practice yoga for astounding health benefits Can a 5000-year-old system be the ultimate body healer? Did you know yoga can make you smarter and…
High Fiber Diet – Fire up your fiber intake for these health benefits! Regular bowels, healthy detox, higher immunity, and guaranteed weight loss - a high fiber diet can bring all…
social media adddiction
Your health in the age of Social Media: Why is digital detox a necessity? Did you know that more than 400 million people are dangerously addicted to social media? Are you one…
Fluoride: An indispensible mineral or a potential toxin ? Fluoride, the main ingredient of toothpaste, has shown a great potential as a cleanser. However, how much fluoride…
diverticulitis diet
Diverticulitis diet: The right way to eat if you suffer from the disease Are you suffering from diverticultis but clueless about your diet ? Read this complete plan for diverticulitis diet…
liver detox facts
7 liver detox facts and why ignoring these could kill you! Are you taking care of this organ that handles over 500 different vital functions in your body? Your…
Creatine: Is this the right peak athletic-performance supplement for you? Creatine is the amino acid that boosts our energy. Did you know creatine supplements can help you reach…
Isagenix diet
Isagenix Diet: Do you really need liquid meal replacements to lose weight? Isagenix Diet - What are liquid meal replacements and why is the world going ga-ga over them? Are…
tasty protein foods chicken
Experts believe these are the best protein foods for you Why are proteins called the building blocks of life? Is the vegan diet really devoid of protein-rich foods?…
Glutathione: Probably the strongest antioxidant known to mankind An antioxidant with ample potential to transform your body, glutathione is one of the most critical substances secreted…
eating myths debunked
8 ‘healthy eating’ myths you believed until now Is a zero-carb diet really healthy for you? Are organic products worth their cost? Did you know how…
Dragon Fruit – Blessing from Nature’s Basket The dragon fruit is packed with nutrients and yet low on calories and is the dream food that…
Maltitol: Things you must know about this artificial sweetener Sugar alcohols are produced by fruits and vegetables. Maltitol is an artificially produced sugar alcohol and is used…
lifestyle diseases
The Big 5 lifestyle diseases: How your everyday living might be killing you You'd be shocked to know how unhealthy and potentially fatal your everyday routine could be. Has the modern…
sugar toxic health
Sugar: 7 new shocking truths revealed about the sweet poison Can drinking soda bring you closer to death? Is sugar slowly poisoning you and your family? You would…
occupational hazards types
Occupational Hazards: How to vouch for your health at your workplace Occupational hazards affect millions worldwide. Chemical spills, faulty wires, deadly pathogen, and work-stress can happen anytime. Follow these…
hidden causes obesity
8 hidden causes of obesity you probably didn’t know! Did you know that around 2 billion people worldwide are either overweight or obese? Are you too a…
carrageenan seaweed
Carrageenan: How a simple seaweed extract could better your gut health & immunity Eat more ice cream to prevent cold and flu? –With carrageenan you get one simple seaweed extract that…
Panera bread steak arugula
Panera Bread: The truth behind this “healthy” restaurant chain What to order and what to avoid when dining at Panera Bread ? Know more about this popular…
Salt dangers
Sodium chloride: The wonders and dangers of the simple table salt Sodium chloride is a salt containing sodium and chlorine ions at a 1:1 ratio. It is edible and…
Paleo diet man
Paleo Diet: Is eating like the Caveman the right way to go? Paleo diet is the world's oldest diet; dating back to 2.5 million years ago. Why is this prehistoric…
stress depressed anxiety
Are you depressed or just stressed? Know when to see a doctor Why are some people more anxious than others? Is being depressed the same as feeling sad? Have you…
lose weight fast
12 easy and instant steps to successful weight loss Do you want to lose weight without losing your mind? Does weight loss always mean saying goodbye to…
sleep deprivation
Don’t let your sleep deficit grow into memory loss or heart attack Why is sleep important for us? How could sleep deprivation harm you? We bet you didn't know about…
quinoa salad
Quinoa : A prodigous superfood you need to include in your diet today! Quinoa - what is so special about this native South American grain that has taken the world by…
boost immunity tips
Step up your defence: 15 proven tips on how to boost your immunity Want to naturally build up a stronger immunity? Tired of frequent colds and runny nose?You will never believe…
vital organ diseases
Common diseases that could cripple your vital organs Brain, heart, kidney, lungs, and liver - these vital organs are indeed vital for your survival. However, these…
bananas exercise
10 health reasons why you should go “bananas” over bananas! Bananas:The world's most popular fruit comes with a host of unbelievable health benefits. Find out how you can…
stevia side effects
Stevia: A healthy sugar substitute or yet another risky additive? Stevia is a plant native to South America.  It has been used as a natural sugar substitute and…
Pomegranate: Why are they called ruby red pearls of health? The shrub Punicagranatum yields a red fruit which is what you normally call pomegranate. The fruit is round…
black seed oil benefits
Black Seed Oil: What secret benefits could it bestow on your health? Black seeds or nigella seeds are tiny packets of health brimming with amazing benefits. Find out why should…
nature health benefits
Green Healing: The amazing health benefits of being in nature You have no idea what sitting in a closed room does to your body and mind.Can a stroll…
dance health benefits
5 unbelievable effects of dance on your overall health! You enjoy dancing, but did you know what else it does to your body? Dancing is not only…
acne removal tips
Anatomy of acne: 7 instant steps to kiss those zits goodbye Blackheads, whiteheads, or pimples-call them what you may. Acne is never good news.Did you know some of the…
L-theanine attention
L-Theanine: Better sleep, higher focus, and many other benefits Did you know that L-theanine found in green tea can make you sleep better and be focused at…
oral hygiene tips
6 shocking consequences of bad oral hygiene (and how to avoid them) Did you know bad breath is not just turning off, but also harms your body in ways you…
autoimmune diseases facts
Autoimmune Diseases: Find out if your body is attacking you right now Did you know your body can harm itself? What are autoimmune diseases and why does it harm some…
Pumpkin Seeds: Why pumpkins are more than just for pies! Pumpkins have been long associated with Halloween carvings and delicious pies. But did you know that pumpkin seeds…
BCAAs powder
BCAA: Now get more out of your workouts with this miracle protein BCAAs are counted as one of the best supplements for increasing your physical endurance. Find out what are…
avocado benefits
Avocado: 15 reasons why this fruit should be a staple in your diet Did you know that the word avocado literally means "testicles". Don't get grossed out as this power-packed fruit…
Garlic health benefits cloves
Garlic: Nature’s white pill as an effective home remedy What are the secrets hidden in these tiny white pills? Find out the immense health benefits of using…
gallbladder diet tomato
Gallbladder surgery :Tips on post-operative care and diet What to eat post a gallbladder surgery? What are the key things to avoid if you had a…
Juice Plus: Can you really replace actual fruits with pills?  Juice Plus supplements intend to fill nutritional gaps present in our daily diet. But how successful have they…
cancer facts
8 hard-hitting truths no one tells you about cancer Did you know that 1.5 million new cases of cancer are reported every year? Can second-hand smoking kill…
Low carb diet
8 appetizing and mouth-watering recipes that every low-carb dieter should try Looking for delicious recipes that will fix your hunger pang without adding those pesky carbs? Look no further…
fitness routine fun
10 fantastic ways to make your fitness routine more fun! Are you too bored to exercise? Do you avoid gym cause it's too monotonous? Looking for fun and…
turmeric skin
We bet you didn’t know that turmeric could be this beneficial! Did you know that turmeric, a humble ingredient found in most Indian kitchens could cure countless ailments and…
Serotonin happiness
Serotonin : What you didn’t know about this “feel-good” chemical Serotonin : Did you know that this "feel-good" hormone could well impact your sleep cycle, sex drive, appetite,…
Keto diet healthy
Keto Diet: Did you know you could eat fats to burn fats? Keto diet - A wonder diet that lets you eat fats and lose weight too! Read on to…
Spirulina: Battle diabetes and cholesterol with this blue-green algae Spirulina, a species of salt water algae, has now become a billion dollar industry. How you can use…
low carb diet meal
Low carb diet : Go high on fats and low on carbs for a leaner body! Did you know that sugar is the new fat? Going low on carbs and high on fats &…
nutritional yeast bread
Nutritional Yeast : How can a fungi culture be good for your body? Nutritional yeast: How a simple culture of fungi can transform your skin, digestion, immunity , and much more.…
ashwagandha brain
Ashwagandha: The best-kept secret of Ayurveda now revealed! Ashwagandha literally means "smell of horse". Don't get bogged down by that one tiny detail because this ayurveduic…
ADHD forgetful
ADD versus ADHD: What are the fundamental differences? Is every hyperactive child a patient of ADHD? Do adults display symptoms of ADHD as well? What is…
calories healthy
Calories: How to keep a check on these for faster weight loss Did you know you can burn calories while sleeping? Calorie-burning is what causes weight loss. How much should…
Kale: With more iron than beef, this superfood is the ultimate way to lose weight Checkmate meat-eaters; with kale, vegans now have the ultimate iron-rich superfood as their ally that can protect from…
passion fruit juice
Passion fruit: How one exotic fruit can help you fight infections and cancer! Passion fruit: Why does this exotic fruit have such an enticing name? And how can it protect you…
How to make the apple cider vinegar diet work for you? Apple cider vinegar diet is a popular choice among health enthusiasts.Find out why nutritionists believe this could be…
How much protein
Proteins: What is the right protein-intake for your specific needs? As we all know protein is an essential macronutrient indispensible to good health and body. But how much…
Horny Goat Weed: Can it improve libido in human beings too? This plant got its name as Horny Goat Weed when one of the goats feeding on the plant…
hYdroxycut pills
Hydroxycut: How safe are these so-called weight loss supplements? Hydroxycut is a blend of several different ingredients formulated to promote weight loss; powered by a key weight…
alcohol toxic
7 startling facts that will make you quit alcohol today Does drinking really make you friendly and happy? How many calories does a can of cold beer add…
Manuka Honey Manuka honey is a specific type of honey produced by honey bees that collect nectar from the flowers…
Healthy pregnancy tips
How to have a healthy pregnancy: Essential tips to remember What to expect when growing a life within you? How important are prenatal vitamins anyway? Don't make these…
paleo keto diet
Paleo vs. Keto: Which diet plan is best suited for your body goals? Is eating like a caveman the right way to go? Can you really eat fats to burn fats…
aspartame or sugar
Aspartame – Hidden truths about this storm in a teacup Aspartame, the artificial sweetener, has gone under the scanner on several occasions for allegedly doing more harm than…
improve digestion weight loss
Power up your gut: 8 proven steps on how to improve your digestion Did you know you have a colony of bacteria in your gut that help you in digesting food?…