Why might a vaccine make someone sick?

Please help this is due today.

If they are taking a vaccine such as the flu shot, the dead strand of flu might be too active or still alive and can make you sick. especially if you have a low immune system

Well a vaccine can make some sick by someone getting side affects due to a ingredient in the vaccine

Use the internet to you

The return of the wolf to yellowstone national park will probably affect the bird population to some degree, not significantly. while wolves will hunt birds when necessary, they prefer to hunt larger prey. the bird population will most likely only be affected when hunting is scarce for the wolves. birds of prey will also probably not be affected as much as other birds who spend more time on the ground hunting for food as the tend to spend more time in the air or in trees since they do not need to stay on the ground for long due to the nature of the way they hunt.