Emirates has signed a partnership agreement with Nigeria's Arik Air – Arik Air just launched their new loyalty program Arik Affinity Wings last month.
While Arik Air's hubs in Nigeria's Lagos and Abuja won't be high on most people's travel list, they are perfectly located to connect Western Africa. The loyalty program allows flights starting from just 4,000 miles round trip within Nigeria and there is a 1,000 sign-up miles credit.
Arik Air uses the A380 for the London – Lagos and makes a polished impression unlike many of the continent's airlines.
Western Africa has woefully few safe airlines – in fact, to go from Abidjan, Ivory Coast to Freetown, Liberia (just 677 miles apart), most connections will route you through Brussels or Paris making it a ride of ~6,000 miles flown!
Royal Air Maroc provides many of the connections and Emirates has a number of tag-on flights in the area as well.