The recent times covid-19 has created an unconditioned stimuli in every ones life.
In the beginning of the pandemic the streets went empty (it was an unconditioned response i.e. fear of catching the virus) due to the fear of the same
People where in homes as Alexa , Ben and Brent. People were scared and sad (unconditioned response) due to the scenario.
a new conditioned response of wearing mask and using sanitizers was created to the corona stimuli.
People started wearing mask as if it was a regular part of the life: distance was maintained; sanitizers were with everyone. ( A conditioned response was created with people after corona as a stimuli)
This opened and people went back to their normal life.(here extinction of response of fear has occurred due to vaccine but conditioned response of wearing mask is still there) .