Vaccines are drugs that are used to protect the body against infectious diseases. They are designed to stimulate the body’s immune system, which is the body’s natural defence against illness.

Unlike antibiotics, which are used to treat bacterial infections, vaccines do not actually kill the pathogen. Instead, they trigger the person’s white blood cells to produce antibodies that can fight off the infection. If the person is exposed to the pathogen in the future, white blood cells quickly produce the right antibodies. This stops the person from becoming very ill.

There are many different types of vaccines, and they are used to protect against a wide range of viral and bacterial infections, such as influenza (flu), measles and COVID-19.

Influenza (flu)• Fever
• Dry cough
• Fatigue
• Sore throat
Measles• Fever
• Cough
• Red, watery eyes
• Runny nose
• Rash
COVID-19• Fever
• Dry cough
• Fatigue
• Loss of taste/smell

The discovery of vaccines

The development of vaccines has had a major impact on public health. One of the first vaccines was created by the English scientist Edward Jenner in the 18th century.

Jenner’s research focused on smallpox, a highly contagious and deadly disease that affected a large portion of the population. He noticed that people who milked cows and had contracted cowpox (a milder disease) seemed to be immune to smallpox. He decided to test this observation by deliberately infecting a young boy with cowpox and then exposing him to smallpox. The boy did not get sick, which showed that cowpox could provide immunity to smallpox.

Jenner’s vaccine was made by taking pus from a cowpox blister and inserting it into a small cut on the skin. This process, called vaccination, triggered an immune response in the body and provided immunity to smallpox. This played a key role in eradicating smallpox, which was declared eradicated by the World Health Organisation in 1980.

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