At the turn of the 20^th Century, the average life expectancy of an Australian male was around 55.2 years, while the Australian woman could expect to live for an average of 58.8 years.

Over the past 100 years, our life expectancy has increased dramatically.

According to the Australian Bureau of Statistics (ABS), in the past 20 years alone, there has been a 263 per cent increase in the number of Aussies aged 100 and older.

The ABS cites the average life expectancy of Australians (as of December, 2014) is 82.1 years – that’s close to a 25-year increase in the past century.

Our increased life expectancy may be largely attributed to the ongoing development of vaccines,  antibiotics and advances in medical technology.

Today we may easily access a plethora of medicines designed to prevent or cure diseases that were historically unavailable.

In recognition of ongoing medical advances, we wish to reflect on various ‘modern’ scientific triumphs that were responsible for curing some of the most deadly diseases on earth.

Rabies

First recorded around 4,000 years ago, rabies may represent the oldest infectious disease known to humankind.

Defined by the World Health Organization (WHO) as a vaccine-preventable viral disease prevalent in more than 150 countries, rabies is a zoonotic disease, which means it’s transferred from animals to humans.

Rabies is characterised by a reaction in the nervous system, which causes excitement, paranoia, anxiety, confusion and even fear of water. Another common symptom of rabies is hyper-salivation, or foaming at the mouth.

Throughout the 20^th century, rabies was a major killer worldwide. In the USA, it was not until the 1940’s when dogs could be successfully vaccinated through a single inoculation, that fear of rabies began to dissipate.

Today, this life-threatening virus is completely vaccine preventable. There are three approaches to vaccinating against rabies.

1. The first is animal inoculation. The most cost-effective strategy for preventing rabies in people is by eliminating rabies in dogs through vaccination.
2. Human vaccination represents the second approach to vaccinating against rabies. In Australia, the rabies vaccine protects against rabies as well as Australian Bat Lyssavirus – which is closely related to the classical rabies virus and is present among all four types of flying foxes (commonly known as ‘fruit bats’), with a subtype also found in insectivorous bats that are prevalent across mainland Australia. First discovered in Australian flying foxes in 1996, Australian Bat Lyssavirus has claimed the lives of three Australians, all in Queensland, the most recent occurring in February, 2013
3. Post-exposure prophylaxis is the third approach to vaccinating rabies. This measure has proven extremely effective in stopping the illness post- exposure. According to WHO, “every year, more than 15 million people worldwide receive a post-exposure vaccination to prevent the disease – this is estimated to prevent hundreds of thousands of rabies deaths annually.”

Despite the fact that rabies is vaccine preventable (or cured), hundreds of thousands of people continue to die from this illness, mostly in Africa and Asia, solely due to lack of funds to purchase the vaccine. In terms of rabies- related mortality, WHO estimates more than 40 per cent of children under the age of 15 die from rabies.

Polio

In the late 1940’s and early 1950’s, Australia was in the grip of its worst ever polio epidemic. At its height, polio was responsible for the deaths of more than 10,000 Australians each year.

Overcoming polio – previously one of the most dreaded childhood diseases – represents one of the greatest success stories of modern medical science.

Polio is now eradicated throughout most of the developed world.

In 1952, the first effective polio vaccine was developed by American medical researcher, Jonas Salk.

The Salk virus, made available to humans in 1957, comprised an injected dose of inactivated (dead) poliovirus. Introduced to Australia in the late 50’s, Salk’s vaccine almost completely eradicated the disease.

In the late 50’s, a contemporary of Salk, Albert Sabin, was working with a live poliovirus to develop an alternative treatment. In 1962, Sabin’s vaccine was made available to humans as an oral polio vaccine.

Since the advent of the polio vaccine, the disease has almost vanished.

According to WHO, in 1988, there were an estimated 350,000 cases of polio globally. In 2013, there were 416 reported cases – a more than 99 per cent decrease in the virus.

Yellow fever

Yellow fever is a tropical virus, spread by mosquitoes. It is characterised by a yellowing of the skin and affects the liver and kidneys, causing fever, jaundice, loss of appetite, chills, muscle pains and headaches.

Once contracted, there is no known cure for yellow fever. Hence the virus has a high mortality rate. An estimated 50 per cent of people who experience a severe case of the illness will die.

WHO regulations cite vaccination as the single most important measure for preventing yellow fever. A yellow fever vaccine has been used commercially since the 1950’s. It is safe, effective and provides immunity within one week in 95 per cent of those vaccinated.

In 2013, WHO concluded that one dose of yellow fever vaccine is sufficient to protect against the disease for life. Yellow fever vaccine is included on the WHO list of Essential Medicines.

Measles

Historically, measles was a devastating disease. US estimates suggest that in the decade prior to the introduction of the measles vaccine, more than three million Americans were infected with measles, of whom 400 to 500 died, 48,000 were hospitalised and 1,000 were diagnosed with chronic disability, directly resulting from the disease.

Since the introduction of the MMR (measles, mumps and rubella) vaccine in 1971, the rate of disease has decreased by 99 per cent.

In March, 2014, WHO announced measles elimination had been achieved in Australia.

In Australia, the MMR vaccine combined with the chicken pox vaccine (the combo-treatment is commonly known as the MMRV vaccine) is funded through the National Immunisation Program (NIP) for children aged 18 months and above.

Smallpox

In the 20^th century alone, smallpox – an acute contagious disease that primarily attacks the body’s skin cells, leading to bumps all over the body – was responsible for between 300 to 500 million deaths.

In 1798, English Physician and Scientist, Dr Edward Jenner developed the first vaccine for smallpox. Through his pioneering work, Dr Jenner is thought to be responsible for saving more lives than any other human.

Due to the insatiable nature of smallpox, WHO pioneered a global immunisation program to eradicate the disease.

In 1980, smallpox was the first disease officially declared to be “eradicated.” The last known case of smallpox was caused by a laboratory accident, which led to the death of a person in Birmingham, England in 1978.

It’s amazing to see how far medical science and technology has progressed in the past century alone. And we continue to make significant leaps and bounds, building on the discoveries of our forefathers.

Today, we live in an age in which many diseases may be cured. It’s hard to even begin to imagine what the next century has in store.