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Colds, Flu and Immunity 

The Common Cold is a viral infection of the upper respiratory tract. It is a catarrhal disorder recognised by episodes of sneezing, acute rhinitis with nasal discharge and congestion, chills and a possible temperature.

Influenza (“The Flu”) is an acute viral infection of the respiratory tract. It is highly contagious and is caused by 1 of 3 influenza virus strains (A, B, and C).

The immune system is the body’s inbuilt system of protection for every organ from outside biological microorganisms. It is a natural or acquired (active or passive) resistance to disease.


There are more than 200 different viruses that can cause a cold. Some of the more common ones include rhinovirus, corona virus, respiratory syncytial virus (RSV), influenza (flu) and para-influenza, each one with their own severity.

They are usually left to run their course within 1 to 2 weeks without complications and require little medical attention unless such complications occur.

Complications may include the development of more serious conditions such as bronchitis, pneumonia, ear infections, sinusitis or attacks of asthma in susceptible people.

Once a cold takes hold symptoms like a tickly nose and/or itchy throat usually begin within 2 or 3 days, followed by sneezing and a watery nasal discharge.

From 1 to 3 days discharges become more profuse. It is at this time that you are at your most contagious.

Because there are so many causative viruses there are currently no medicinal cures for the cold. Preventative medication that will strengthen your immune system has therefore proven significantly successful and is generally the recommended route.

Influenza (“The Flu”)

The Flu is a more serious contagious viral disease of the respiratory tract, causing inflammation, sneezing, coughing, a sore throat and fevers.

The differences between a cold and The Flu: Colds and flu are often mistaken for one another due to the similarities of their symptoms. There are of course many overlaps in the symptomatic area, but with flu being of a more severe nature it usually also produces more uncomfortable and debilitating sensations… Over 100 different viruses can cause colds; only a few cause flu. You cannot catch flu from cold temperatures. Symptoms like fever and headache are common with flu, but not usually seen in the common cold. Sneezing, a sore throat, a stuffy nose and tiredness are common to both, although fatigue is much more prevalent in flu. The Flu is more serious than a cold as it has the potential of leading to other complications such as pneumonia, bronchitis, sinusitis, ear infection and even meningitis.


The immune system is a network of specialized cells that work to clear infection and to protect your body from the millions of bacteria and viruses you may be exposed to every day.

Foreign organisms are everywhere. They are in our air, our food and our water. They are unavoidable. It is therefore up to your immune system to protect your body from their invasion into your system, causing illness and disease.

'Innate' and 'Acquired' immunity

Your immunity can be innate or acquired:

Your innate immunity prevents the entry of foreign bodies into your tissues. If they do take hold it is your innate immunity that eliminates them before they have a chance to cause disease.

Your acquired immunity only occurs in response to an actual infection as the immune system adapts itself to fight these foreign bodies and rid your body of potential disease.

To understand how this really works try thinking about what happens to the human body after it dies. Once the body dies the immune system completely shuts down. Bacteria and parasites then quickly invade the body. With no immune system to fight it, the bacteria and parasites soon ‘eat up’ every tissue until only the skeleton remains. Whilst you are alive your working immune system stops this from happening.

Immune system biology

Immune cells are produced in your bone marrow, the most relevant cells of which are called the lymphocytes.

You have B cell lymphocytes (in your bone marrow). These produce antibodies and attach to any foreign bodies in your system ready for their destruction. T cell lymphocytes (in your thymus) then attack and destroy any diseased cells and foreign bodies until your infection is clear.

Immune system disorders

Immunodeficiency is where your immune system is not working correctly and is significantly reduced in its ability to fight infection and disease.

At the other extreme, an overactive immune system is where your immune system malfunctions in a different way and fails to distinguish between your body’s own cells and the invading foreign bodies. Not being able to make this distinction, your immune system begins to attack your own body, destroying healthy tissue and causing further debilitation.

Immune system disorders can be caused by prolonged poor eating habits, an insufficient nutritional balance, alcohol or drug abuse and exposure to environmental toxins. They can also come from the inheritance of a faulty or mutated gene.

Colds, flu and your immune system

Due to their commonality and the sheer number of causative viruses, especially with regard to different strains of cold, your immune system cannot possibly cope with them alone. It needs support. The only way to do this is to take responsibility for disease prevention yourself and help your immune system reach and maintain peak performance.

A healthy body results in an effective immune support system, and vice versa!

The poor level of immunity that is so commonly seen in many societies today is due mostly to poor dietary habits, excessive uses of antibiotics, environmental factors and natural internal nutritional imbalances. Unfortunately most people are unaware of how heavily influenced their bodies are by internal nutritional requirements.

To ensure your immune system gains the strength it needs to keep your body healthy and functioning optimally, you need to obtain all the nutrients you need to sustain good chemical, nutritional and hormonal balance, giving your natural defenses a sound ‘helping hand’.

If you are at particular risk of catching a viral condition, such as if you work in a hospital, live with infected people, travel a lot and visit countries where you may come into contact with viruses, you should consider giving your immune system a regular ‘lift’ for that added insurance.

You are at greater risk of infection and need to be more aware of taking preventive steps is you:

  • Are 65 years or over
  • Have lung, heart, or kidney problems, a blood disorder, or suffer from a metabolic disease
  • Have a lowered immunity due to prolonged use of medications, or
  • Are pregnant

As for the cold, there are currently no medical cures for flu. Preventative medicine and keeping your immune system in peak conditions are therefore the only significantly successful methods of beating these conditions.

Bird Flu

Recently there has been widespread global concern regarding the outbreak of bird flu and the implications this brings to human health. This is largely hyped out of proportion and fueled by 'special interest' groups. It is unlikely to be a real threat but nonetheless like all potential viral threats you are at less risk if you keep your body healthy.

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  • In 2003 more than 200,000 people were hospitalized from flu complications. Of this number resulting deaths reached approx. 36,000.
  • In 2004/2005 around 45,000 people died from influenza or related complications. Elderly patients formed around 20,000 of these deaths.
  • The most common cold is the rhinovirus, which causes about 35% of all colds.

During the last 100 years:

  • The Spanish flu of 1918-19 caused 20 million deaths.
  • The Asian flu of 1957-58 resulted in 500,000 deaths in the US.
  • The Hong Kong flu of 1968-69 caused 34,000 deaths in the US.

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A cold is caught by inhaling the virus from someone sneezing close by, or by touching your nose, eyes or mouth after you have touched something contaminated with the virus.

The flu is caught when an infected person coughs, sneezes, or speaks and sends minute flu viruses into the air for other people to breathe in.

The chill theory and the viral theory

Experts denote 2 further theories as to how the cold and flu viruses spread.

The chill theory tells us that there is a higher incidence of colds and flu in the winter, therefore infection is down to the cold and wet weather.

The viral theory is contrary to this in that it says colds are caught more frequently in winter because people spend more time indoors with other people and with heating on high, providing an easy and vibrant environment in which foreign organisms can breed and spread.

Ultimately, if our immune system is at its strongest and performing at its best possible level, it would be able to fight such occurrences, no matter what the origins.

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Signs & Symptoms

Symptoms of a cold or of flu can be extremely similar. However, flu does produce more serious and debilitating effects.

Often you can continue your usual daily routines even with a cold, whereas with the flu your body requires more rest and may have difficulty performing usual tasks.

Symptoms include any/all of the following:

The Common Cold The Flu Both
Slight fever
Runny nose
Potential high fever
Dry cough
Joint aches and stiffness
Flushed face
Dizziness and/or vomiting
Breathing difficulties or wheezing
Swollen glands
Slow thinking / confusion
Muscle aches
Runny nose
Nasal congestion
Sore Throat
Watery eyes
Sinus or ear pain

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Conventional Treatments

Common medications include:

  • Painkillers, e.g. Paracetamol
  • Decongestant sprays
  • Oral decongestants (tablets or syrup)
  • Expectorants
  • Antihistamines

NB: Antibiotics are not helpful in relieving symptoms of the common cold as it is a virus, not a bacteria, and they may even prolong it.

Antiviral medications

Amantadine, Rimantadine
Active against influenza A, Amantadine and Rimantadine have been known to cause side effects such as insomnia and anxiety, nausea and loss of appetite. In severe cases side effects such as seizures have been reported. Use of Amantadine (and Rimantadine) has been associated with central nervous system side effects including nervousness, anxiety, insomnia and light-headedness.

Tamiflu (Oseltamivir Phosphate) is approved to treat type A and B influenza. It is an oral antiviral drug for the treatment of uncomplicated flu. Its use in people with chronic heart or lung diseases, kidney disease or other underlying high-risk conditions should be with extreme caution.

Side effects can include nausea, vomiting, diarrhea, bronchitis, stomach pain, dizziness and headaches.

Tamiflu has also been in the public eye concerning its potential effectiveness against bird flu. Stockpiles continue in the event of a pandemic which is possibly politically motivated rather than based on sound science.

Oseltamivir, Zanamivir
Active against influenza A and B. Oseltamivir is often prescribed for children.
These drugs inhibit the activity of the influenza virus M2 protein, which forms a channel in the virus membrane. As a result the virus cannot replicate after it enters a cell.

Zanamivir and Oseltamivir are called neuraminidase inhibitors. They work by blocking this enzyme's activity, preventing new virus particles from being released thereby stemming the spread of infection.

Each of these medicines has side effects that can include nausea and vomiting, wheezing or breathing problems, headache and diarrhea.

Pain relievers

Used to relieve body aches, headaches, sore throats and fever.

Side effects of these painkillers can include allergic reactions, black or bloody stools, nausea, vomiting, abdominal pain, fever, ringing in the ears, dizziness, heartburn, drowsiness and headache. None of these should be taken on a prolonged basis.

Used to relieve body aches, headaches, sore throats and fever.Side effects of these painkillers can include allergic reactions, black or bloody stools, nausea, vomiting, abdominal pain, fever, ringing in the ears, dizziness, heartburn, drowsiness and headache. None of these should be taken on a prolonged basis.

e.g. Sudafed
Used to help relieve a stuffy nose, ear congestion or ear popping.

Side effects include potential tachycardia, palpitations, headache, dizziness or nausea, restlessness, weakness, dysuria, insomnia, convulsions, arrhythmias and hypotension.

Cough syrups
e.g. Chlorpheniramine, Dextromethorphan
These are used to suppress certain kinds of coughs, although it is important to note that coughing is useful because it removes secretions from your throat.

Side effects can include allergic reaction, excessively dry eyes, nose and mouth, drowsiness and dizziness, blurred vision, difficulty in urinating and hyperactivity.

e.g. Hydroxyzine hydrochloride, Diphenhydramine hydrochloride, Atemiozole

These are used to relieve allergy symptoms, but can cause side effects such as drowsiness, dry mouth, dizziness, sleepiness, upset stomach, decreased coordination, fatigue, weight gain, chest congestion, fluttery heartbeat, loss of appetite and vision problems.

Flu Injections
Flu jabs have been well advertised over recent years, especially to the elderly or people at high-risk, as a way of reducing the incidence of flu. It contains already killed flu viruses that will cause your body to fight off infection from the live flu virus should it enter your system. It is given as a single injection in the upper arm and is updated each year to include the most current strains.

However, they rarely get the 'strains' right and the effectiveness of flu shots are at best marginal.

Side effects can include flu-like symptoms for a few days afterwards, such as headaches and low-grade fever.

There is also a nasal version of the vaccine, but this is made from live viruses and as such causes more pronounced side effects, including runny nose, headache, vomiting, muscular aches and fever.

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