A vaccination record card is shown during a COVID-19 vaccination drive for Spring Branch Independent School District education workers March 16, in Houston. (David J. Phillip • Associated Press/The Minnesota Star Tribune)

The author of "Vaccine passports could be a shot in the arm" (Opinion Exchange, March 16) is right. Yes, we do need a vaccine passport.

But he's also wrong, because there's no need for new legislative wrangling in Washington to create one.

There already is a vaccine passport. It's easy to get. And its source is impeccable.

Nicknamed "the yellow card," it's a small, passport-sized yellow pamphlet officially titled "International Certificate of Vaccination as approved by the World Health Organization."

The yellow card is an official medical record, recognized worldwide, of the diseases you've been immunized against.

I've always carried my yellow card and my passport together in my handbag, even at home. Mainly, that's so I always know where they both are, but it's also out of nostalgia.

When I was traveling a lot for the Star Tribune's Travel section, I wanted to be able to turn on a dime and hit the road fast, so I kept my documents super-handy. It still feels good to have both passports up to date and within easy reach, without having to rummage through a desk drawer for paper medical records or troll my clinic's bewildering trove of records online.

My current yellow card lists rabies boosters, shingles shots, flu vaccine, typhoid vaccine, pneumonia vaccine, diphtheria/tetanus/pertussis vaccine and yellow fever vaccine.

The yellow fever vaccine has been available since 1938, but there are lots of destinations around the world still being stalked by this killer, including ones you might not expect — cities as well as vacation getaways.

The WHO's website (www.who.int) reports that "32 African countries are now considered at risk of yellow fever, with a total population of 610 million people, among which more than 219 million live in urban settings." Yellow fever, it adds, "is endemic in 10 South and Central American countries and in several Caribbean islands."

As COVID showed us this year and yellow fever continues to prove, killer diseases are still out there, still evolving, still dangerous. The precautions that countries take to protect themselves also evolve.

Some countries won't let you in — really won't, so don't argue at customs — without medical proof that you've had the right vaccines or gotten them far enough in advance of your trip for them to be fully protective when you arrive. Those rules change periodically, and a travel clinic here at home is the best bet for finding out what the current rules are for the places you're going.

There are many travel clinics in Minnesota now, some within large clinic networks, some independents. Their staff will evaluate and update your vaccine status, depending on your destinations, advise you on other health risks there and provide a yellow card if you don't already have one.

Of course, a yellow card is not a magic charm. Some vaccines expire and have to be re-given. Others — smallpox, for example — need to be given only once in your lifetime, typically in childhood.

I'd bet good money that every anti-vaccine activist my age in America bears the same permanent smallpox-vaccine scar that I've had on my left shoulder since grade school.

Imagine your body and face covered with scars like that, if you managed to survive the real thing before the vaccine came in. Medical science fought a long time to win the smallpox battle for us, which makes this scar a badge of honor.

According to Dr. Anthony Fauci, smallpox is the only killer plague that has been completely eliminated, worldwide. The only one. And it took centuries to get it done.

The disease was first recorded in Asia in the 1500s. A smallpox vaccine was first used in the U.S. in 1799. America had a final outbreak of smallpox in 1949, and only in 1980 was smallpox declared eradicated worldwide.

Some of the available travel vaccines may surprise you. Though very rare now, bubonic plague still crops up in the United States, and — as we all now know — viruses travel with people.

All the immunizations I've had are listed in my yellow card. It's also where I've just stapled the little proof-of-vaccination card I got when I was given my COVID vaccine. Keep yours handy too.

Catherine Watson was the Star Tribune's first travel editor, from 1978 to 2004.