Create object instance from casted std::shared_ptr

I have vector which holds a set of shared pointers:

std::vector<std::shared_ptr<Derived>> originalVector;

At some point it implicitly casted to Base shared pointers, it looks like:

std::vector<std::shared_ptr<Base>>* castedVector;

How to add an Derived item to casted vector? Apparently I can emplace an empty std::shared_ptr into it, does this new shared pointer know anything about type it holds, can it create an object of this type?