Getting Technical
VACCINES REMOVE OR REDUCE RISKS OF DANGEROUS INFECTIONS
By Charles Nicolson
CHARLES NICOLSON
Charles Nicolson has a physics and chemistry degree from Natal University which he subsequently put to good use by applying speciality chemicals in mining and industrial processes where water is a major factor . This created an enduring interest in water technology , a passion that expanded to the HVAC industry in 1984 when he joined BHT Water Treatment . Since then , water technology in HVAC water circuits has continued to be an abiding interest .
In 1796 , Edward Jenner , who was one of the first English doctors to include planned regular examinations in treatment programmes for his patients , noticed that patients who suffered from cowpox did not appear to get sick from a far more deadly and highly infectious disease – smallpox .
To confirm his observations , and after obtaining permission from the foster parents of a young orphaned boy , Jenner deliberately infected the boy with cowpox by taking liquid from another patient ’ s actual cowpox sores and scratching some of it into the boy ’ s skin . Six weeks later , using the same method , he scratched some liquid smallpox venom into the boy .
After almost one month , no symptoms which would indicate smallpox illness occurred . The success of this planned experiment by Jenner became recognised as the first scientific demonstration of injecting a person with one virus to provide protection against other and potentially more dangerous viruses .
In his description of this technique of injecting people with cowpox to provide protection ( now termed ‘ immunity ’) against smallpox , Jenner introduced the word ‘ vaccine ’ which he composed from the scientific name for cowpox , ‘ variola vaccina ’; - vaccina meaning ‘ of the cow ’. The orphan boy concerned was also the first person ever to get
a vaccination and it was not until almost a hundred years later that vaccinations started to be used again , starting with protection against cholera in 1879 .
Thereafter , vaccines against other diseases were devised and applied more widely and with increasing frequency .
Vaccines now protect against many different diseases , such as : cervical cancer , cholera , diptheria , hepatitis B , influenza , measles , mumps , pneumonia , polio , rabies , tetanus , typhoid , varicella and yellow fever . Many other vaccines are currently under development including those that protect against ebola and malaria . Cervical cancer provides an interesting example of a high success rate – virtually all cervical cancer cases start with a sexually transmitted human papillomavirus ( HPV ) infection . If given before exposure to the virus , vaccination offers the best protection against the disease . Following vaccination , reductions of 90 % or even more in HPV
All images supplied by contributor
Just a few millilitres is enough . Early USA advertisement for vaccination .
infections in teenage girls and young women have been demonstrated by studies conducted in Australia , Belgium , Germany , New Zealand , Sweden , the United Kingdom and the United States of America .
Vaccines do not act directly against invading organisms , commonly referred to as ‘ germs ’, but enable natural defences of bodies to recognise invading germs such as viruses or bacteria and also to produce antibodies which are proteins tailored specifically to fight infections .
The memory functions induced by vaccines continue to operate , providing protection against diseases for years , decades or even a lifetime . This is what makes vaccines so effective . Rather than having to treat a disease after it occurs , vaccines prevent sickness in the first place . In addition , people who have been vaccinated are less likely to transmit viruses or bacteria to others including those who cannot be vaccinated due to health conditions such as allergies , or advanced age .
www . hvacronline . co . za RACA Journal I April 2021 33