The price of fake vaccination cards on the dark web has increased by 100 per cent since President Biden announced the full implementation of the vaccination mandate.

A few days before the president announced that all businesses with more than 100 employees must require vaccinations or weekly testing, the price of a fake vaccination card was about $100. The day after the announcement, the average price shot up to $200.

Biden also strengthened the vaccine mandate for federal workers and contractors last Thursday, requiring them to be vaccinated and eliminating the alternative of weekly testing.

The number of sellers cashing in on the anti-vaccine market has also surged, from about 1,000 to more than 10,000, according to data provided by Israeli security firm Check Point.

According to Check Point researchers monitoring the dark web, the number of users of fake vaccine cards in Telegram groups has increased fivefold. For months, fake vaccine cards have popped up on Amazon, Etsy, eBay, Facebook, Instagram and other marketplaces.

In April, a bipartisan coalition of attorneys general from 47 states sent a letter to the CEOs of Twitter, Shopify and eBay demanding that ads or links selling fake cards be taken down.

Many websites have blacklisted keywords related to fake cards, but fake cards continue to appear on messaging app apps, chat forums and the dark web.

In July, the Department of Justice announced its first prosecution of fake vaccine certificates, with California naturopathic doctor Julie Martz charged with one count of wire fraud and one count of misrepresentation in connection with health care matters. And on Aug. 17, TangTang Zao, a Chicago-based pharmacist, was arrested for selling dozens of fake vaccine cards for just $10 each. Zao allegedly sold blank but genuine CDC vaccination cards and was charged with 12 counts of theft of government property. If convicted, he faces a 10-year sentence on each count.

"To put such a small price on the security of our nation is not only an insult to those who did their jobs in the fight to stop COVID-19, but it is a federal crime with serious consequences," said Special Agent in Charge Emmerson Buie Jr. of the FBI's Chicago District Office.

On Aug. 31, Jasmine Clifford, a New Jersey woman known as @antivaxmomma on Instagram, was charged along with 14 others in a scheme to peddle more than 250 fake vaccination cards on Instagram for $200. For an additional $250, co-conspirator Nadayza Barkley, who worked at a New York medical clinic, allegedly entered the buyers' names into a state digital database to obtain digital vaccination cards for New York.

Three Vermont police officers, who are also under investigation by the FBI, have resigned for running a fake vaccination card scheme.

Customs and Border Protection says it has seized thousands of fake vaccination cards entering the U.S. in the past few months.

Last month, the agency discovered a shipment of fake vaccination cards from Shenzhen, China, to Memphis that was riddled with typos and misspellings.CBP said it was the 15th such shipment that night, none of which were hidden inside cargo containers, although they were destined for different cities.CBP said 121 vaccination cards were seized in Memphis alone, for a total of 3,017.