Around 260 police officers searched 70 apartments and a company in the Rhineland for fake vaccination cards.
The investigations were mainly directed against a medical assistant, the Cologne public prosecutor reported on Tuesday.
Their private home was also searched.
Numerous counterfeit vaccination cards were secured in various objects.
Mobile phones were also confiscated as evidence.
There were no arrests.
In the run-up to the action, no arrest warrants had been requested.
It will also be determined against 59 potential customers.
In addition, 15 other procedures are being investigated in which, among other things, fake vaccination cards are said to have been presented in pharmacies or to the employer for digitization.
A total of 77 suspects between the ages of 16 and 74 are being targeted by the authorities.
The investigation group "Stempel" had already started a major search operation three weeks ago.
At that time, a good 200 police officers were on duty and a total of 40 apartments were searched.
This time investigators were in Cologne, Leverkusen, the Rhein-Erft district, the Mettmann district and in the Oberberg district.