Kent Fire And Rescue service along with other partners were called just after 1:38 pm on Monday afternoon, following the serious collision on the London-bound carriageway.
The Kent Sussex and Surrey air ambulance landed on the coast-bound carriageway.
Emergency doctors treated those involved before one patient was airlifted to a major trauma centre by air ambulance after being freed from the wreckage by firefighters who used spreaders and extrication equipment to gain access to the mangled wreckage