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VACCINATION antibiotic how it works
People can be immunised against a pathogen through vaccination. Different vaccines are needed for
different pathogens. penicillin breaks down cell walls
Vaccination involves putting a small amount of an inactive form of a pathogen, or dead pathogen, into
the body. Vaccines can contain: erythromycin stops protein synthesis
· live pathogens treated to make them harmless
· harmless fragments of the pathogen neomycin stops protein synthesis
· toxins produced by pathogens
· dead pathogens vancomycin stops protein synthesis
These all act as antigens. When injected into the body, they stimulate white blood cells to produce
antibodies against the pathogen. ciprofloxacin stops DNA replication
Because the vaccine contains only a weakened or harmless version of a pathogen, the vaccinated
person is not in danger of developing disease - although some people may suffer a mild reaction. If the
person does get infected by the pathogen later, the required lymphocytes are able to reproduce rapidly
and destroy it.
Vaccines in early childhood can give protection
against many serious diseases. Sometimes more than PENICILLIN
one vaccine is given at a time, like the MMR triple A bacterium damaged and distorted by
vaccine against mumps, measles and rubella. penicillin
Sometimes vaccine boosters are needed, because the The first antibiotic - penicillin - was
immune response 'memory' weakens over time. Anti- discovered in 1928 by Alexander Fleming. He
tetanus injections may need to be repeated every ten noticed that some bacteria he had left in a
years. petri dish had been killed by naturally
occurring penicillium mould.
Resistance Since the discovery of penicillin, many other
Bacterial strains can develop resistance to antibiotics. antibiotics have been discovered or
This happens because of natural selection. In a large developed. Most antibiotics used in
population of bacteria, there may be some cells that medicine have been altered chemically to
are not affected by the antibiotic. These cells survive make them more effective and safer for
and reproduce, producing even more bacteria that humans
are not affected by the antibiotic.
MRSA is methicillin-resistant staphylococcus aureus. Cleanliness
It is very dangerous because it is resistant to most One simple way to reduce the risk of infection is to maintain personal hygiene and to keep
antibiotics. It is important to avoid over-use of hospitals clean. In the 19th century, Ignaz Semmelweis realised the importance of cleanliness in
antibiotics, so we can slow down, or stop, the hospitals. However, although his ideas were successful, they were ignored at the time because
development of other strains of resistant bacteria. people did not know that diseases were caused by pathogens that could be killed.…read more


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