On the heels of fake vaccine cards showing up on the Dark Web, counterfeit versions of Pfizer’s COVID-19 vaccine have been identified in Mexico and Poland, according to The Wall Street Journal.

Pfizer tested seized vials in separate investigations and confirmed that what was being offered to people who were desperate to get vaccinated was not the company’s mRNA shot. In the Poland case, the substance in the vials appears to be an anti-wrinkle treatment.

So far, no one seems to have been harmed by the fakes. Polish officials stopped distribution before anyone received the shot. Mexican officials say roughly 80 people were dosed.

The news of counterfeit vaccines both underscores the international demand and could be the latest rallying point for anti-vaxxers, many of whom are refusing to get the shot in the U.S. It’s especially concerning with recent news that a third dose of the vaccine might be required within 12 months.

While availability of COVID vaccines is becoming more widespread in the U.S., other countries have been unable to move as fast—and some, like India, are facing shortages, in part because of export limits.

To date, the Department of Homeland Security says no counterfeit vaccines have been discovered in the U.S., the Journal reports.

The government has long been wary of fake vaccines and treatments, knowing how eager Americans are to get back to normal life. In November, the Food and Drug Administration warned “The FDA is particularly concerned that these deceptive and misleading products might cause Americans to delay or stop appropriate medical treatment, leading to serious and life-threatening harm.”

Home test kits were some of the first tools of criminals looking to prey on the public. Investigators seized tens of thousands of fake kits in the months before they were made available to the public. In the U.S. alone, more than 1,000 fake websites have been removed during the pandemic per day.