 Hey everybody, Dr. O here. In this short video, I just want to talk about the term herd immunity, so we'll put it into context more when we're talking about vaccines, but I just want to get the terminology straight here with all these other terminology videos. So herd immunity is when the majority of a population have developed immunity. So obviously vaccines are a way to do that, but there is also natural immunity. You could even look over history of what's called genetic immunity, which means that the people that are alive today are the ancestors of the survivors that made it through certain diseases that are just endemic to given areas. So the ones that couldn't fight off that pathogen didn't live. So not a big deal now. But so herd immunity is when the majority of a population are immune to something. The number that I always say is 85%. You're going to hear slightly different numbers, but I think that herd immunity is reached when 85% of a population is immune. So why does this matter? If I'm not one of the 85% that are immune to something, herd immunity is protecting me, but not individually. If I do come into contact with that disease and I do get it, I will still get sick and either die or get better. But what herd immunity does is it creates a barrier around me that minimizes the chances that I'm going to come into contact with it. So if you think about a population, every person around you is either a potential carrier of a disease that can spread it to you or a potential barrier that can stop the spread of disease from someone. So when I'm in a classroom, I usually talk about how someone in the front of the class has a disease. Someone in the back of the class is not immune to that disease. Well, if all the people between them have had the disease or are immune to it because of vaccination or whatever, they're going to stop the spread of that disease to the back row where the person would acquire it. Of course, it's a silly analogy, but it works pretty good. So herd immunity obviously matters in the healthcare setting. Think about the fact that if you're working in a long-term care facility, a nursing home or something like that, and you're working with immunocompromised individuals, you, as the healthcare workers, you are the barrier to the spread of disease to them. So you can hopefully form that herd immunity that will minimize the chances that your patients get sick. All right. So that is herd immunity. We'll talk about it more. It is a very important term. It's the reason vaccination programs need certain numbers to actually be effective. So I hope this helps. Have a wonderful day. Be blessed.