From cholera to COVID: a brief history of vaccines

Every minute, eight children’s lives are saved by vaccines, according to the World Health Organization (WHO). Previously fatal diseases like smallpox and polio have been virtually eliminated around the world. But how did this lifesaving breakthrough come about?

The idea of using cells from infectious diseases to stimulate the human body’s immune system to fight them is not new. Historians say people were using basic forms of immunization centuries ago.

Vaccines have come a long way since then, with inoculations now available to tackle most of the world’s worst infections. The COVID-19 pandemic saw new vaccines developed in record time - ready in just 12 months compared to the usual average of 10 to 15 years.

The remarkable success of vaccines has not been without its challenges - one of the main ones being misinformation and anti-vaccination sentiment, says WebMD, which can be traced back to the 1860s with smallpox immunization fears.

The pandemic also derailed immunization efforts in many countries. The WHO says the suspension of vaccinations in over 68 countries has put at least 80 million children under the age of one at risk.

With studies reporting increasing numbers of cases of measles, diphtheria, polio and dengue and other vaccine-preventable diseases, the WHO has called for the urgent resumption of immunizations across the world.

So, as we mark World Immunization Week, let’s look at some of the milestones in the remarkable journey to a vaccine-protected world.

As early as the 1500s, people were using simple forms of vaccinations, smearing smallpox on torn skin to create immunity, according to Gavi, the global vaccines alliance.

The process, known as variolation, was recorded as being practised in China in the 17th century and it is said to have cut the death rate from smallpox dramatically. Only around 2% of people died from variolation compared to 30% who caught the disease.

Interest in variolation in North America was sparked by Cotton Mather, a New England Christian minister who read a scientific paper about its use in Turkey. He discovered that one of his servants, who was from what is now Libya, had undergone the procedure.

At around the same date, Lady Mary Wortley Montagu, a smallpox survivor and wife of the British ambassador to Constantinople (today’s Istanbul), had her three-year-old son inoculated in the city and returned home to promote the benefits of vaccination.

But it was not until 1796 that British country doctor Edward Jenner studied the effects scientifically. Noticing that women working at a local dairy were immune to smallpox because they had already suffered from cowpox, he vaccinated a child with cowpox.

After what historians call the first modern vaccination - named after vaccinia, the Latin name for cowpox - the boy was then exposed to smallpox with no ill effects. For nearly a century afterwards, vaccination meant preventing smallpox.

Perhaps best-known today for inventing a method of preserving milk, Louis Pasteur discovered a vaccine against chicken cholera in 1879 after mistakenly leaving a vial of the virus open to the elements for a month. Chickens injected with the neglected virus became ill but recovered swiftly.

Pasteur reasoned that the virus had weakened, or attenuated. His accidental discovery opened the door to producing vaccines in the laboratory by creating a less potent form of a virus that would stimulate immunity without harming the patient.

Pasteur went on to develop successful vaccines against anthrax and rabies. In 1885, Spanish doctor Jaime Ferrán in 1885 created a human cholera vaccine. And in 1896 two German scientists perfected a vaccine against typhoid.

The 20th century saw the creation of vaccines against tuberculosis, tetanus and diphtheria. In 1951, South African virologist Max Theiler won a Nobel prize for a vaccine against yellow fever and in 1955, US scientists announced a successful vaccine against polio.

In 1967, the WHO set a 10-year target to eliminate smallpox from the world by vaccination. The programme was called Target Zero. By the end of 1970, South America was smallpox-free and the virus was eliminated from Asia by 1975.

In 1977, nearly 200 years after Edward Jenner’s pioneering vaccination, Ali Maow Maalin, a 23-year-old hospital cook in Somalia, became the last person to suffer from naturally acquired smallpox. He was vaccinated and survived. In 1980, the WHO declared smallpox eradicated.

After the COVID-19 outbreak was confirmed, work began on vaccines at astonishing speed and, within 12 months, new vaccines were being tested and approved. The previous fastest vaccine turnaround was six years for mumps.

The speed was the result of groundbreaking previous work on vaccines for HIV, MERS and SARS, which used RNA and DNA genetic material to stimulate cells to produce “spike proteins” which create antibodies to fight a virus.

The story of vaccines is far from over. “Despite rapid advances … in response to COVID-19, more investment is urgently needed in new vaccines and new vaccine technologies,” says Gavi.

“Because, with more than 300 emerging infectious diseases identified since 1940, new pandemic threats lie in the future.”