How are the ms drugs avonex (interferon beta 1a) and copaxone distinguished from each other?

Multiple: Avonex (interferon beta 1a) is an interferon, given into the muscle once weekly, and copaxone, injected under skin daily, is a polymer. But why use needles, as we have 3 oral agents, and all are as potent or more potent than Avonex (interferon beta 1a) and copaxone.

Avonex (interferon beta 1a) v Copaxone: Avonex (interferon beta 1a) is an injection given to a muscle once per week. It is a deep shot. Copaxone is a superficial shot given under the skin every day. The retail costs of the medicines are about the same. They are both expensive; insurance coverage may be important. Avonex (interferon beta 1a) sometimes may cause flu-like side effect symptoms, copaxone may not. Both can cause irritation by the injection site.