For the second time in less than a month, customs officials working at O’Hare International Airport have seized packages containing several counterfeit COVID-19 vaccination cards shipped from overseas.

U.S. Customs and Border Protection officers working Monday at the airport’s international mail facility located two packages that collectively carried 41 forged vaccine cards resembling the authentic Centers for Disease Control and Prevention certificates given to those who have been vaccinated against COVID-19.

“These dishonest vendors that are producing and sending these counterfeit cards are putting the American population in danger with every card they produce,” LaFonda Sutton-Burke, the director of field operations in the CBP’s Chicago field office, said in a statement. “Ordering and producing these cards is illegal and the only reason this is being done is to make a quick dollar, when getting the vaccination is free.”

The packages, which purportedly contained greeting cards, had been shipped from China with intended destinations at residential addresses in Bartelso, Illinois, and Houston, Texas. Officials said the fake vaccine cards were identified based on their “low-quality appearance and other discrepancies.”

Customs officials previously announced that 19 counterfeit vaccination cards had been recovered at O’Hare from inside a parcel heading to an Ohio address on Aug. 31.

“This is a dangerous game that people are playing,” Shane Campbell, the Customs and Border Protection’s Chicago area port director, said in a statement. “Not only is it a public health risk, but it is also illegal and comes with serious consequences for violators.”