ST. LOUIS, Mo. (KTVI) – If you hold a COVID-19 vaccination card, you are part of an exclusive, albeit growing, club.

Nearly 30% of people living in the United States have received at least one dose of the COVID-19 vaccine. And these cards are the proof you got the shot.

“That’s the official card that the CDC puts out, so it’s been validated by the federal government. You’ll notice a small number and lettering system on it. That’s the official markings of the federal government,” said Dr. Alex Garza, head of the St. Louis Metropolitan Pandemic Task Force.

However, there are companies selling COVID-19 vaccination ID cards. One is Castle Branch, which sells a “real vaccination ID card.”

For $19.95, you can order a card the company says will provide, “verified physical evidence of an individual’s vaccination status, complete with sophisticated anti-counterfeit technology, to ensure authenticity and peace of mind.”

On the Castle Branch website, it acknowledges that the CDC offers vaccination cards but claims they’re “highly susceptible to fraud, can be easily forged and are prone to damage or destruction.”

It also notes the company is not part of the “Vaccine Credential Initiative,” a group comprised of healthcare organizations, tech firms, non-profits and startups working to empower consumers to conveniently access, store and share digital COVID-19 vaccination records.

“There could be products out there that could be more durable than a paper card. I get it,” Garza said, referring to the CDC card. “I’m sure there are people out there making false cards, and yes, this card could be manipulated. But as of right now, that is the only valid card that demonstrates that you’ve been vaccinated against COVID-19.”

When it comes to protecting the card you receive from the CDC, Garza said, “I don’t see anything wrong if you feel you want to protect your card by laminating it. I don’t think there’s any issues with that.”

For now, Garza says he doesn’t think vaccine documentation beyond what the CDC provides is necessary.

“That should really be the only documentation you need at this time,” Garza said.

The CDC recommends taking a photo of your vaccine card as a backup. It also urges you to avoid posting pictures of the cards online.

If you misplace your card, the CDC advises that you go back to where you got the shot and try to get another card.

KTVI tried to contact the CDC and Castle Branch for this story but did not receive an immediate response.