Well, I heard some people talking just the other day. And they said you were gonna put me on a shelf. Well, let me tell you I've got some news for you. And you'll soon find out it's true. And then you'll have to eat your lunch all by yourself. Coz I'm al-ready gone, and I'm fee-ling strong.
So they need booster shots to build up immunity. Also, some people tend to lose their immunity over time if they don't receive the recommended booster shots. So booster doses are given to ensure that the immunity does build up even for those children in whom it didn't with the first vaccine. For some immunisations, your baby will need a course of vaccines to build up his defences and to provide life-long immunity.
Brake boosters are used only on power brakes, not manual brakes. The booster's function is to give more braking power with minimal pressure on the brake pedal. If the booster is not working properly, you will still have brakes, but the brake pedal will be very hard to push. A brake booster is what gives power brakes their power. It works on vacuum from the engine. The booster pushes on the master cylinder with the pressure applied to the booster by stepping on the brake. If the engine is off, it cannot get vacuum, therefore the brakes will be hard when the engine is off.