I often talk about how vaccines are a miracle. They’ve saved millions of lives. But exactly how do they work? Well, they connect to the human immune system, which is itself, really phenomenal. So, when a germ gets inside and attacks your body, the immune system sees unusual foreign shapes
on the surface and then special cells in your body called
white blood cells create antibodies that connect up. Then your immune system knows to go and kill this foreign object. The idea of the vaccine is instead of having to get sick the first time, to develop this immunity, we take something that looks like a foreign
bug, teach the immune system the shape of this
foreign object so it’s ready to attack with antibodies
very, very quickly when the real bug shows up. So, you can avoid lots of diseases, if you’ve been properly vaccinated. And that’s why Gavi was created. Gavi came up with the money and a plan to get vaccines out to all the kids of the world. If you go back to 1990, about 9% of all children died before the age of five. Now, that number is about 4% and these vaccines, that Gavi got out, have been critical to that. So, it really is a miracle. You can read more about vaccines and the investments we’ve made at GatesLetter.com.