Herd immunity: What is it and how does it benefit us ?

Herd immunity is the idea that in a community not everyone has to be vaccinated in order to prevent the disease from spreading. Only around 85% of the population has to be vaccinated, allowing people who are allergic or unable to have the vaccine to be protected against the disease. This is because of the probability that the person who is unvaccinated meeting another unvaccinated person that has the disease is very small. Therefore herd immunity prevents the spread of harmful diseases to vulnerable people.