The Vaccination Booklet for Everyone

Sometimes, it can be like running a marathon. With smallpox, it took almost two hundred years from administering the first vaccine to actually eradicating the disease. At others, it's more like a sprint: The first COVID-19 vaccines were approved just a year after the virus broke out. But then in certain circumstances, the sprint is followed by an obstacle course. This is what happens in the case of the flu virus – new vaccines have to be developed because of the constant stream of variants and mutants emerging every year. The situation is similar where coronaviruses are concerned and there are times when it resembles the hare and the hedgehog race. But whatever happens, vaccine research is more than equipped to cope.

Imagine the processes in the body are similar to a concert. The heart keeps the beat, the organs are the instruments and blood circulation ensures that the orchestra plays together as one. When a virus invades the body, it produces 'sounds' that are not part of the body's concert. It can sound as odd as an instrument that's out of tune or be as shrill as a trumpet that doesn't fit in or belong. If the viruses are allowed to multiply undisturbed, the sound of that single trumpet becomes an increasingly unpleasant noise that drowns out everything else. But if the body's immune system – its security service – stops the troublemaker from getting onto the stage, then the concert is able to continue undisturbed. That's the kind of endless harmony a vaccination is designed to achieve.

It all began with milkmaid Sarah Nelmes in the English town of Berkeley. Like many farm workers, she suffered from cowpox (a harmless skin infection) but was somehow spared from contracting smallpox, which often resulted in death. On 14 May 1796, country doctor Edward Jenner drew some of the fluid from Sarah's cowpox blisters and transferred it to his gardener's eight-year-old son. Seven weeks later, Jenner then infected the boy with smallpox. The boy remained healthy and didn't contract the disease. This highly unethical human trial, which today would be expressly prohibited by law, made medical history and ushered in the era of vaccination. In the 225 years since Jenner's discovery, vaccines have since taken away the fear of more than two dozen infectious diseases – and that's only the beginning.

"All for one and one for all!" – that was the cry of the Three Musketeers in Alexandre Dumas' novel of the same name. That kind of unity and cohesion, of looking out for one another, not only gives fictional heroes courage and strength – it's also one of the best-known recipes for success. In the course of evolution, we've survived not as individuals, but as communities – as families, tribes and clans. People who get vaccinated primarily protect themselves, improving their health, life expectancy and quality of life. And in doing so, they protect their families, friends and neighbours, and other people as well.