Here is a good example
Ignaz Semmelweis is known as the father of hand hygiene.
In 1886 Semmelweis imposed a new rule mandating hand washing.
The rates of death in his maternity ward fell dramatically.
This was the first proof that cleansing hands could prevent infection.
However, the innovation was not popular with everyone, some were disgruntled and they stopped washing their hands.
Semmelweis tried to persuade others in European hospitals of the benefits of handwashing, but to no avail.
A few years later in Scutari, Italy, Florence Nightingale implemented handwashing and other hygiene practices in the war hospital in which she worked. Nightingale’s handwashing practices achieved a reduction in infections.
Sadly, the hand hygiene practices promoted by Semmelweis and Nightingale were not widely adopted. In general, handwashing promotion stood still for over a century. It was not until the 1980s, when a string of foodborne outbreaks and healthcare-associated infections led to public concern that the United States Centers for Disease Control and Prevention identified hand hygiene as an important way to prevent the spread of infection. In doing so, they heralded the first nationally endorsed hand hygiene guidelines, and many more have followed.