Vaccination is a miracle of modern medicine. In the past 50 years, it's saved more lives worldwide than any other medical product or procedure. However, the fascinating story of vaccination goes back all the way to Ancient Greece.
429 BC: Thucydides notices that people who survive smallpox do not get reinfected
As long ago as 429 BC, the Greek historian Thucydides observed that those who survived the smallpox plague in Athens did not become reinfected with the disease.
900 AD: Chinese discover variolation
The Chinese were the first to discover and use a primitive form of vaccination called variolation. It was carried out as early as the 10th century, and particularly between the 14th and 17th centuries.
The aim was to prevent smallpox by exposing healthy people to tissue from the scabs caused by the disease. They did this by either putting it under the skin or, more often, inserting powdered scabs from smallpox pustules up the nose.
1700s: Variolation spreads around the world
Variolation eventually spread to Turkey, and arrived in England in the early 18th century. At this time, smallpox was the most infectious disease in Europe. It struck rich and poor alike, and killed up to one-fifth of those infected in numerous epidemics.
Variolation caused mild illness, but although it occasionally caused death, smallpox rates were lower in populations that tried it.
1796: Edward Jenner discovers vaccination
British physician Dr Edward Jenner (pictured) discovered vaccination in its modern form and proved to the scientific community that it worked.
1803: Royal Jennerian Institute founded
Support for vaccination grew. Jenner was awarded government funding, and in 1803 the Royal Jennerian Institute was founded. Vaccination became popular throughout Europe and, soon after, the US.
1870s: Violent opposition to vaccination
Although vaccination was taken up enthusiastically by many, there was some violent opposition as it became more widespread. People found it hard to believe that it really worked. They also felt it took away people's civil liberties, particularly when it was compulsory.
1880s: A vaccine against rabies
Louis Pasteur improved vaccination even more and developed a rabies vaccine. As the science of immunology developed and scientists began to understand more about how diseases worked, other vaccines were created.
1890: Emil von Behring discovers the basis of diphtheria and tetanus vaccines
German scientist Emil von Behring was awarded the first Nobel Prize in Physiology or Medicine.
Japanese physician and bacteriologist Shibasaburo Kitasato discovered the antitoxins of diphtheria and tetanus. He demonstrated that animals injected with small amounts of the tetanus toxin became immune to the disease.
1920s: Vaccines become widely available
By the end of the 1920s, vaccines for diphtheria, tetanus, whooping cough and tuberculosis (TB) were all available.
Vaccination spread across the globe – although these early vaccines were crude, they worked. The first vaccination programmes dramatically reduced the number of deaths from disease and were crucial in establishing the concept of preventative public health measures.
1955: Polio vaccination begins
Polio vaccination was introduced in the UK, dramatically reducing the number of cases of the disease. Nowadays, polio is extremely rare and is close to being completely eliminated from the planet.
1956: WHO fights to eradicate smallpox
The first attempt to use the smallpox vaccine on a global scale began when the World Health Organization (WHO) decided to try to eradicate smallpox across the world.
1980: Smallpox eradicated from the world
Smallpox was declared as being eradicated in 1980. It was one of the most remarkable achievements in the history of medicine.
2008: Cervical cancer scientist awarded Nobel Prize
Professor Harald zur Hausen discovered that cervical cancer was caused by a virus, making it possible to develop a vaccine for the disease.
The scientist proved that a group of viruses called human papillomaviruses (HPV) caused cervical cancer. This discovery led to the development of the HPV vaccine, which protects against cervical cancer, and is now widely available.
2008: NHS vaccinates girls against cancer
In England, the NHS cervical cancer vaccination programme began, whereby all girls aged 12 to 13 are offered HPV vaccination to protect them against cervical cancer. It is the first time that a routine universal vaccine has been given to prevent a type of cancer.
2013: NHS vaccinates against shingles, rotavirus and children's flu
The NHS vaccination programme saw the introduction of rotavirus vaccination for babies and a shingles vaccine for over-70s. A children's flu vaccine was also launched. This is given as a nasal spray rather than an injection.
2015: NHS vaccinates babies against meningitis B
The NHS vaccination programme saw the introduction of Men B vaccination for babies. The programme is the first national, routine, universal and publicly funded Men B vaccination programme in the world.