Humans have been battling disease as long as we have existed. With no understanding of hygiene, germs, bacteria or viruses until extremely recently, illness was frightening and potentially deadly. Populations were regularly ravaged by plague, smallpox, typhus and cholera to name but a few: these epidemics had huge impacts on economic, social and political developments across the world.
Attempts to immunise populations are thought to have been going on for nearly a millennium, and breakthroughs on the development of vaccines in more recent history have fundamentally changed our relationship with disease as illnesses that would once have decimated populations are now practically confined to history books. Our mastery of vaccines has changed the world more than almost any other discovery in modern medicine.
First known vaccinations – China, c. 1400
Variolation was the earliest form of inoculation: scabs were taken from people suffering from a mild smallpox infection, ground into a powder and then blown up the nostril of a healthy person. Occasionally the pustules of a sufferer were sliced into, then a healthy person’s skin was scratched: a gruesome but effective method, as spreading the disease by blood often resulted in a milder case of smallpox for the person being inoculated.
Whilst both methods normally resulted in a mild case of smallpox, most people recovered and developed immunity when they did so. Records suggest that the practice was widespread in parts of China and India by the 16th century, and Emperor K’ang Hsi even had his children inoculated.
Variolation reaches Europe – England, 1721
Reports on Chinese variolation practices reached Western Europe around 1700, but little notice was taken of them. It was an aristocrat, Lady Mary Wortley Montagu, who popularised the practice in England. Having contracted smallpox herself in 1715, she observed variolation when in Istanbul and had her son inoculated there.
On her return to England, she had her daughter inoculated against smallpox via variolation in front of the physicians of the Royal Court, and further tests on prisoners proved its general effectiveness. Variolation was quickly accepted into mainstream science in England.
Edward Jenner creates the first successful smallpox vaccine – England, 1796
On 14 May 1796, Edward Jenner inoculated the 8-year-old James Phipps with matter from a cowpox sore of a milkmaid. Phipps fell ill briefly before making a full recovery. Jenner later infected Phipps with matter from a smallpox sore: the boy remained healthy.
Jenner published a pamphlet entitled ‘An Inquiry into the Causes and Effects of the Variolae Vaccinae, a Disease discovered in some of the Western Counties of England, particularly Gloucestershire, and known by the name of the Cow Pox’ which slowly received recognition and word of Jenner’s success spread.
By the early 1800s, vaccination was actively being encouraged over variolation, and nations as far away as America and Russia had begun championing vaccination.
Smallpox vaccinations begin in South America – Caracas, 1803
The New World, as it was known, had been particularly affected by smallpox when it first arrived in the 1520s. Huge tracts of the native population had been wiped out by the disease.
In 1803, King Charles IV of Spain had one of his physicians, Francisco Xavier de Balmis, along with 22 children, set sail for South America in order to begin smallpox vaccinations there. By the time they reached Caracas, only one of the children (who were being used as live hosts) still had a visible cowpox pustule from which to begin vaccination with.
Vaccination becomes law – Germany, 1874
In 1874, Germany made smallpox vaccination compulsory by law. Unsurprisingly, smallpox deaths dropped rapidly in subsequent years. They were far from the last to introduce mandatory vaccinations.
In 1902, Cambridge, Massachusetts introduced mandatory smallpox vaccination. One resident took this decision to the Supreme Court, which eventually ruled in favour of mandatory vaccines in the name of public health if and when necessary. Even in the present day this ruling is upheld in state courts.
The first laboratory vaccine developed – France, 1879
Louis Pasteur, one of the biggest figures in immunology, was investigating chicken cholera when he discovered attenuation, the process of weakening a strain of bacteria over time. He accidentally successfully vaccinated chickens against chicken cholera in 1879, sparking a whole new dimension of thought in immunology.
Pasteur’s discovery helped him go on to develop vaccines for anthrax and rabies, and the idea of a live vaccine is one which is still very much in use today. By the 1890s, vaccine development was jumping ahead in leaps and bounds. The discovery that glycerin acted as a germicide further helped improve the safety and efficacy of these early vaccines.
Behring discovers antitoxins – Berlin, 1890-5
Emil von Behring, a German physiologist, pioneered the use of antitoxins as a form of inoculation against diphtheria. He used blood from an animal which was infected with diphtheria to inject into a human to create what’s known as passive immunity.
This method was far from foolproof however, and diphtheria antitoxin is not recommended for use today. Serum sickness (mixing animal and human blood) was common and anaphylaxis was not unknown.
Typhoid vaccines transform warfare – America, 1914
By 1914, much of the US Army had been vaccinated against typhoid, and ordinary citizens were beginning to be so as well. Stopping soldiers dying of typhoid transformed warfare: a highly infectious disease, it had been rampant in the unhygienic and cramped quarters occupied by the military in times of war.
The first effective polio vaccine is rolled out – America, 1952
By the early 1950s, the United States was in the midst of a polio epidemic. The disease had taken hold in Europe and America in the early 20th century with particular virulence, and it generally struck children, often disabling them for life.
In 1952, Jonas Salk headed up the team that developed the first effective polio vaccine, which was licenced in 1955. Thanks to major vaccination campaigns, rates of polio dropped dramatically and the virus is almost eradicated today.
Smallpox eradicated – Somalia, 1980
The last natural known case of smallpox was recorded in Somalia in 1977. Prior to this, a huge, worldwide vaccination campaign had been undertaken, with the WHO undertaking massive vaccine drives across the developing world. In 1980, the WHO formally declared smallpox eradicated: a major victory in the history of vaccination.
Vaccines produced in record time to combat Covid-10 – England, Germany, America, 2020
When the Covid-19 pandemic hit in early 2020, scientists around the world scrambled to understand the disease so that they could begin trying to create a vaccine for it. Thanks to the rapid advancement of our understanding of viruses and vaccines, the first clinical trials for the Pfizer BioNTech vaccine took place in April of the same year.
There are now multiple types of vaccines for Covid-19, each of which use a slightly different but almost equally effective way of introducing the virus to the body’s immune system in small quantities so that it can recognise and produce antibodies in a controlled situation.
Various vaccines were approved for mass vaccination programmes after rigorous testing in late 2020 and early 2021, marking the start of one of the biggest vaccine drives in history. To date it’s believed Covid-19 vaccines have saved at least a million lives across the world, as well as millions more hospitalisations and cases.