The Manga Akira was prolific because of the influence that it had on the rest of manga and Japanese animae. The Akira featured a dark urban scene and a more somber tone. That really resonated with the audience. The Akira had such an impact that the impact is still being felt in Japanese fiction today.
If you asked the average Joe to name an anime or a manga, I'm fairly certain that many people would name Akira off the top of their head. It has influenced countless movies, tv series and comics, including those from America. I think it is definitely fair to say that Akira is prolific, if not thee most prolific manga/anime of all time.
The Japanese manga Akira is popular in its native country and worldwide among fans of the anime genre, but that is a niche audience and the manga is relatively unknown outside of these two areas. It may be prolific in the sense that there are fans all over the world, but they are small in number and definitely a minority. Katsuhiro Otomo's post-apocalyptic anime has not caught on with mainstream audiences and probably never will.
No, the manga Akira is not that prolific. In order for something to be prolific, it must be common or very well known. Lots of people must be familiar with the subject before it is considered prolific! Not that many people are familiar with manga Akira. Therefore, manga Akira cannot be that prolific.