You don’t need vaccination against COVID-19 — better yet a vaccine booster — to simply cross the Golden Gate Bridge into San Francisco. But tourists and locals alike will soon need full vaccination, including a booster, in order to participate in some of the city’s most fun activities.

That’s because, as of Feb. 1, the San Francisco Department of Public Health requires that all people eligible for a COVID-19 booster must show proof of the shot if they’re attending indoor events with 500 or more people or outdoor events with 5,000 or more people. That means that COVID-19 vaccine boosters are required to attend most concerts, live shows, conferences and festivals in the city.

San Francisco has some of the most stringent domestic booster requirements, but they may be coming elsewhere too. Hawaii Gov. David Ige said in an interview with the Honolulu Star Advertiser that the state is considering requiring travelers to show proof of a COVID-19 booster shot to be considered fully vaccinated. Within the state, Maui County already has its own booster mandates to enter certain businesses.

The case for getting boosted ahead of travel

If you’re not yet boosted, first consider that vaccine requirements are continually evolving and expanding. San Francisco's new booster requirements kicked in Feb. 1, even though the new rules were only announced on Jan. 10. That gave unboosted travelers only about three weeks to schedule and receive their booster shot before the new rules take effect. People unwilling to get boosted might have to rush to resell nonrefundable show tickets or get a refund on airfare or hotel reservations.

Even without government-imposed mandates, individual businesses and entities such as employers, college campuses and restaurants might require proof of up-to-date vaccination.

If you’re planning domestic travel, accept that booster requirements may be on the table. Have a plan for handling those requirements if they arise; that plan may be to ensure you’ve been recently vaccinated or boosted.

Do I need a booster for international travel?

A few countries have already released booster mandates, at least in some capacity — and it’s likely that others will follow. More common than outright booster mandates are requirements that your most recent dose of the COVID-19 vaccine be taken within a specific timeframe, meaning that people who got vaccinated earlier in the pandemic would need a booster to remain up to date.

For example, travelers to Croatia must be either fully vaccinated with an approved vaccine administered within the past 365 days, with the final dose taken more than 14 days before arrival, or else meet certain other requirements like quarantining, COVID testing, or providing proof of recovery from COVID. However, if you were vaccinated more than a year ago and don’t want to quarantine or take a COVID-19 test, then you’ll need a booster.

Israel’s rules are tougher, requiring not just proof of a negative test taken 72 hours or less before your flight, but also proof of full vaccination or recovery from COVID-19 to enter, unless you have a special permit or Israeli passport. And for most people to be considered fully vaccinated, they must have received their latest dose within the last six months, with the final dose taken at least 14 days before arrival.

Check with your destination’s tourism department not only when booking your trip, but also just ahead of your departure. Booster requirements may quickly change.

Understand the COVID-related documentation you’ll need

Just as booster rules are region-specific, so are the exact means of proving you’re boosted (or vaccinated, for that matter). While a physical copy of your vaccine record is generally accepted, you might not want to take that with you to every activity, as you risk damaging or losing it. Some businesses might be fine with simply seeing a photo of it on your phone.

Apps such as Clear’s Health Pass, which stores digital versions of your card, may work at some establishments. Apps like this can be appealing because they’re typically capable of storing both proof of vaccination and test results in one place.

Maui County spells out its vaccination requirements: In addition to your proof of vaccination, you need a form of ID with the same information as the vaccination record.

For international travel, many countries require that you upload your vaccine proof to their own apps and websites, like Israel's Green Pass. If you’re traveling internationally, check with your destination country’s tourism department for the latest rules. And for all travelers, check local rules, as well as rules enforced by any venues you’re planning to visit.

One more thing: In most places, being boosted is still insufficient for entry. Most countries, including the U.S., require proof of a negative COVID-19 test in order to enter, even if you’re vaccinated. The type of COVID-19 test that’s accepted can vary widely based on where you’re headed. And beware: COVID-19 tests can get pricey, especially if destinations require tests that have a quick turnaround time or come from a specific provider.

Protect your vacation budget with travel insurance

Travel in the COVID-era is inherently risky. Rules and restrictions change without warning, and it's possible that you may get sick ahead of travel.

Buying travel insurance can be a smart money move in the right situation. Though specific coverage varies from provider to provider, these policies can help you get back the nonrefundable money spent upfront on flights, hotels or activities if you cancel travel for covered reasons.

You can maximize coverage by purchasing Cancel for Any Reason (CFAR) travel insurance. Though more costly upfront, you'll be guaranteed that a portion of your down payments will be repaid — regardless of the circumstances.

The bottom line

While only a few countries and cities currently require boosters, the list of those that do is growing, with Hawaii likely becoming the first in the U.S. to issue a statewide requirement. If you’re traveling this year, be prepared for the possibility that you may need to have a booster shot.

More than two years into the pandemic, rules are still constantly changing, so check for the latest updates ahead of your departure.