Essay on pathogenic organism and immunity

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Introduction to Immunity:

There are many ways that pathogenic organisms which can cause disease can enter the body, one of the being via the mouth, and once these organisms have entered the body, we need to have something that can defend us and stop us from getting ill. Our bodies have a natural defence system called the immune system, and when we become ill; our body's white blood cells produce antibodies to fight off the disease that is caused by a pathogen. There are two main groups within the white blood cell; "phagocytes and lymphocytes". (

They each do a different job; the phagocytes (T Cells) ingest and absorb the pathogens or release enzymes to destroy them. Lymphocytes (B cells) bind to the pathogens antigens and destroy them.

When the body is required to produce these specific antibodies, they can ingest and destroy the pathogenic organism. The white blood cells can send messages to the immune system so that the antibodies can be remembered and stored for if there is another attack and therefore they will be immune to that certain disease.

However sometimes we need something to help us produce the right antibodies before the full blast of the disease hits our immune system which in turn could be fatal. When individuals become immune to diseases caused by a virus or a bacterium through artificial means, we call this immunisation.

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There are different ways that a person may be immunised against a disease and there are two main forms; active and passive.

Active immunity, is when the 'attenuated form of the virus'(Pers. Comm., 2010) is given to the patient via injection, which then gets the body to produce the right type of antibodies for that certain disease.

The natural form of active immunity is via infection, and artificial active immunity is via injection of the live attenuated pathogen.

Passive immunity is when blood is extracted from an individual who is already immune to the disease. "This extract of blood is called immune serum" (Pers. Comm., 2010). Immediate protection is normally given from this type of immunity however in most cases it is only temporary and a booster jab is required.

The natural form of passive immunity is via antibodies being passed from a mother's breast milk to a baby or across the placenta. The artificial form of passive immunity is via injection of immune serum.

After the form of immunisation has been given to the individual, there are two stages of response; 'primary and secondary' (Pers. Comm., 2010).

The first few days after the initial immunisation, only a small production of antibodies are within the body and the antibodies are stored in the immune systems memory. However when the body is exposed to the same disease again, the secondary response takes place and many antibodies are produced quickly.

"The aim of immunisation is to protect the individual and prevent the spread of the disease." (Pers. Comm., 2010).

Babies and Young Children:

Young children and babies are at greater risk of catching diseases and infections because their immune system hasn't had a proper chance to develop yet, any disease or infection that they come into contact with will probably be the first time their body has been attacked by that disease and therefore they only have a primary response which is slow and the body will take quite a long time to produce enough antibodies for the safety of the child if enough at all.

This is why children need to be vaccinated from an early age, to give their bodies a head start at producing life saving antibodies.

There are different vaccination schedules for this age group and these include; Diphtheria, Pertussis (whooping cough), Tetanus and Measles, Mumps and Rubella (MMR triple vaccine).

Diphtheria: a bacterial illness

Vaccination schedule:

'One of the leading causes of death in children' within the 1930's ( )

It is given via injection as the combined 'DTaP/IPV/Hib vaccine' (

First dose at 2months old

Booster at 3 and 4months old

Then a final booster at 13-18years

Risks associated with non-immunisation:

Affects the nasal passage and throat

Breathing difficulties

Respiratory failure

Inflammation of the heart (myocarditis) (

Advantages for vaccination:

Reduces the spread of Diphtheria

Safely be given to children

Disadvantages for vaccination:

Can cause a fever

Soreness around the area used for injection

Death (extremely rare)

Pertussis (whooping cough): caused by a bacterium called 'Bordetella Pertussis'.. (

Vaccination Schedule:

Is part of the '5-in-1 vaccine (DTaP/IPV/Hib)' via injection (

First dose at 2months

Booster at 3 and 4 months old

"A pre-school booster vaccine (DTap/IPV) is also given before children start school" (

Risks associated with non-immunisation:



Kidney Failure

Brain damage

Severe dehydration

Advantages for vaccination:

Can be given at a very young age

Is a very safe vaccine

Disadvantages for vaccination:

Soreness around the area used for injection

'Increased crying' (

Can cause a fever

Tetanus: Caused by a bacterium called 'Clostridium tetani'. (

Vaccination schedule:

"The primary course of the tetanus vaccination consists of three doses of the vaccine with a period of one month between each dose" (

Part of the combined DTaP/IPV/Hib vaccination

Given at 2, 3 and 4months of age

4th dose - three years after the primary course as part of the 'pre-school booster' DTP-Polio (

5th dose - aged 13-18years the 'school leavers booster' Td-Polio (

Risks associated with non-immunisation:

Attacks the muscle and nerve system

Stiffness and spasms

"Fractures in the vertebrae" (

Suffocation due to a 'Laryngospasm' (

Advantages for vaccination:

Can be given at any stage between two months and 10 years of age (

Can safely be given to children

Just 3 jabs will give complete protection for 10 years

As tetanus has an incubation period of 21 days, you know for definite that you will be protected

Disadvantages for vaccination:

Can cause seizures 3-7days after the injection

Can cause shock or collapsing

Fever over 105 degrees F


Difficulty breathing

Measles, Mumps and Rubella (triple MMR vaccine):

Immunisation schedule:

The first dose of the MMR vaccine is given at around 13months

A booster is given between the ages of 3 and 5years

Risks associated with non-immunisation;


Painful joints

May cause miscarriages in unborn babies

Swelling of the brain

Blood disorders


Ear infection


Brain damage




Inflammation of the pancreas

Pain and swelling of the testicles in men (

Advantages for vaccination:

Protection from 3 diseases combined into one vaccination

Protects future unborn children

Disadvantages for vaccination:

"Some children may get a very mild form of measles" (

'Bruise like spots'(

Painful and stiff joints

Immunisation for travel:

Although some diseases may not be found in the UK, when we go abroad, we may be at risk of catching a disease. As these diseases may not be common enough in the UK for a regular vaccination, all ages will needed to be vaccinated against before travelling.


Caused by a bacteria, it's an infection of the bowel that can lead to diarrhoea, vomiting and sever dehydration. It can be contracted by drinking dirty water or eating infected foods such as shell-fish.

The vaccination is taken orally in the form of sachets that you dissolve in water.

For children aged 2-6years, 3sachets must be taken one week apart with 'nothing to eat or drink for an hour after taking the vaccination'. (

The course must be completed at least one week before departure.

Areas affected;



Middle East

Peru and some parts of Central America

Cultural issues linked to cholera:

Poor sewage disposal

'Poor sanitation' (

Hepatitis A:

Caused by a virus, it's an infection of the liver which causes it to swell. Other symptoms include "generally feeling unwell, jaundice, sometimes vomiting and a raised temperature." (

It is a single injection 4-6weeks before travel; however it cannot be given to children under the age of one year old.

Areas affected;

Indian subcontinent


Northern and Southern Asia

Central America

Southern and Eastern Europe

Cultural issues linked to Hepatitis A:

Regards to hospitals; dirty needles

Bad sanitation


Caused by a bacterium, symptoms can include abdominal pain, constipation or diarrhoea, nausea and even internal bleeding, ranging from being a 'mild-illness to causing death'. (

A single injection should be given at least 2 weeks before departure or a course of capsules (one taken every other day) should be completed one week before departure. (

Areas affected by Typhoid:


Most of Africa

South Asia

Middle East

Central and South America

Cultural issues linked to Typhoid:

Poor sanitation


Tropical disease spread by night biting mosquitoes which have been infected by the disease. It can cause flu-like symptoms and could develop into a life-threatening illness.


A course of antimalarials is given and one tablet is to be taken everyday for around a week before, during and after travel.

Areas affected by malaria:

Central and South America


Eastern Europe

Southeast Asia

South Pacific

Cultural issues associated with Malaria:

Poor sanitation

Poor education about malaria


"Infection of the central nervous system" (

It's transmitted through bites or saliva from any warm-blooded animal. Symptoms can include anxiety, seizures and disorientation.

Vaccination is via 3 injection doses a month before departure.

Areas affected by rabies:



Latin America

Cultural issues associated with rabies:

Illegal importation of animals (Pers. Comm., 2010).

Immunisation Vs Non-immunisation

In 1998 a small group of researchers published an investigation in a well respected medical journal about the controversy over the MMR jab and whether it had links to autism and bowel diseases.

People were already worried about the MMR jab as there was previous research that it was also linked to Crohn's disease.

Many parents started to refuse having to let their children have the jab. It was suggested that there should be 3seperate jabs however there was never any research to prove that this would be safer.

Advantages for vaccines:

Produces protection from certain diseases

They can safely be given to all ages and are used worldwide

They can prevent further infection of diseases to other individuals

The side effects are lower than what the actual symptoms of the illness are

Vaccinations within the UK are normally free of charge and done on the NHS

Disadvantages for vaccines:

There are always some sort of side effects that can occur after having a vaccination

It may cause an allergic reaction that you may not know about

Some travel vaccinations may cost

With cases like malaria you have to make sure that the tablets are the right tablets for that particular strand of malaria in that particular area otherwise you won't be properly immune