Dr Mathieu Nalpas*
by Dr Mathieu Nalpas*
How was vaccination discovered?
The concept of vaccination and immunisation is very ancient. Evidence of early inoculation to protect people from some disease was found in China. However, the rate of success and protection was not very good. The first modern vaccine was developed in England in the late 18th Century and was used against an infectious disease called smallpox or variola.
Another version of this infection was affecting cows; its name was cowpox or vaccine. The words vaccine and vaccination come from the vaccine disease. The word vaccine comes from the Latin word vacca, which means cow.
In the 18th century, farmers who were milking the cows could get infected with the cowpox virus. They suffered skin lesions and pustules on their hands and arms, but nothing very severe.
During smallpox epidemics, the milkmaids would not become infected with smallpox even when in contact with people suffering from the disease.
In 1796, in England, the scientist Edward Jenner injected material from a cowpox virus into an 8 year old boy with the idea that this would provide the protection needed to save people from deadly outbreaks of the related smallpox virus. It was a success. The eight-year-old was inoculated against the disease and it became the first ever vaccine. Vaccination was born.
What is the immune system?
The immune system protects us against threats and aggression from outside, such as virus and bacteria.
The main cells of our immune system are white blood cells. There are millions of them circulating in our body like a little army watching for something unusual to penetrate the body.
If a microbe invades us, the white blood cells react and multiply into an army of millions of clones who will attack and destroy the invaders. The signs of this immune response working are the coughing, sneezing, inflammation, and fever we experience which work to trap and rid the body of threatening things like bacteria.
Our second line of defence is called adaptive immunity. Special white blood cells create a memory of what the germs look like and how best to fight them. If the same pathogen invades us again in the future, our immune system will have the memory of previous infection and will react much more quickly and effectively. The weapons of adaptive immunity are antibodies.
How do vaccines work?
Doctors use vaccines to trigger a response from the immune system without exposing humans to the full infectious disease.
Vaccines work in two ways.
First, vaccines help to create a standing army of antibodies circulating in our body, ready to trigger fast and effective immune response to an infectious pathogen.
The second mechanism is just as important. It is called herd immunity. It works on a community level. Widespread vaccination reduces the ability of a virus to circulate. With fewer infected people walking around, fewer infected people are passing the disease around, therefore epidemics become very unlikely.
This is very important because some vaccines might be contraindicating for some people, in case of severe allergic reaction for example or immune deficiency.
This herd immunity is essential for preventing outbreaks and protecting vulnerable individuals.
What about side effects of vaccination?
Side effects of vaccines are usually very moderate and not severe. Around the point of injection we can have mild pain, redness and swelling. A low grade fever can occur for a short period of time – nothing to worry about.
Serious reactions to vaccines are very rare, the main one being an allergic reaction that can lead to anaphylactic shock. This kind of allergic reaction can happen with any kind of medicine and even with food. This is not something specific to vaccines and we should not be afraid of allergies with vaccines. Even if such a reaction starts to occur, it is usually treatable with good care – doctors know how to deal with allergies and they have medicines for it.
Where do mistrust and fear about vaccinations come from?
The first reason is amnesia. As far as infectious diseases are concerned, we are living in a much healthier world compared to only 100 years ago. Progress in medicine and hygiene has reduced the burden of countless diseases. Antibiotics and vaccinations are the main actors in this progress.
As a consequence, people forgot about many diseases, they forgot how severe and deadly they could be.
The second reason is misinformation, controversy and misinterpretation. Nowadays, fake and inaccurate information is more likely to be widely spread and, then, will strongly influence and badly damage trusts about vaccinations.
There is a large scientific consensus to say that vaccinations and vaccines are safe and effective. They contributed to eradicate one deadly infectious disease from the planet (smallpox), it dramatically reduced the burden of many other infections and therefore saved millions and millions of lives and it continues to do so every single day. Fear and suspicion about vaccination are irrational and are not based on scientific evidence. — Family Medical Practice
*Dr Mathieu Nalpas is a general practitioner graduated from Lille Medical University in France. He has studied infectious diseases and tropical medicine in French West Indies, has practiced family medicine in France and has managed several isolated health clinics in the Amazon rainforest of French Guyana. He was doing volunteer works in Cambodia, India and Tibet. Dr Nalpas has worked with Doctors Without Borders in HIV/Tuberculosis clinics and in North of France in refugees camps for migrants.
Family Medical Practice was the first foreign-owned primary healthcare provider in Việt Nam, and has consistently remained at the forefront of international-standard medicine since 1995. It offers extensive healthcare and emergency medical services nationwide to Vietnamese, expatriate and corporate customers.
For more advice on any medical topics, visit Family Medical Practice Hanoi at: 298 I Kim Mã, Ba Đình. Tel: (024) 3843 0748. E: [email protected].
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