It was acknowledged before he coined it. He just summed it up better than people had previously. From Wikipedia:

The idea of language as a virus had already been introduced by William S. Burroughs as early as 1962 in his novel The Ticket That Exploded, and continued in The Electronic Revolution, published in 1970 in The Job.

The foundation of memetics in its full modern incarnation was launched by Douglas Rushkoff’s Media Virus: Hidden Agendas in Popular Culture in 1995,[15] and was accelerated with the publication in 1996 of two more books by authors outside the academic mainstream: Virus of the Mind: The New Science of the Meme by former Microsoft executive turned motivational speaker and professional poker-player Richard Brodie, and Thought Contagion: How Belief Spreads Through Society by Aaron Lynch, a mathematician and philosopher who worked for many years as an engineer at Fermilab. Lynch claimed to have conceived his theory totally independently of any contact with academics in the cultural evolutionary sphere, and apparently was not aware of The Selfish Gene until his book was very close to publication.

What Dawkins did was make the concept more analogous to a gene than a virus, but it’s basically the same idea.

https://en.wikipedia.org/wiki/Memetics