The CDC in the USA still defines fully vaccinated as having the first two doses of pfizer or modena. However, a couple of months ago it announced that it was considered changing that to include the booster, if your first two doses was some months ago.
We cancelled a trip to Israel and Jordan since Israel was not open to foreign tourists. Two weeks later, Israel dropped that restriction and we could have gone on the tour.
Planning a trip can be more difficult when countries are constantly changing their requirements.
However, it seems that the trend these days to liberalize entry for travel in many countries. This is true in Europe as well.
When we booked a cruise to the Galapagos Islands for April to replace the tour of Israel and Jordan, the entry requirement was vaccinated (needed a booster if double dose vaccine was some months before) and a COVID19 test.
That changed so that now if fully vaccinated (changed to first two doses) there is no requirement for a COVID19 test. Of not fully vaccinated, a COVID19 test is enough.
I have done some research on the definition of fully vaccinated and found that Germany had (perhaps still has) the fully vaccinated definition that may require a booster. Still, it seems that the UK does nor require the booster.
Does anyone know of a website that has the current entry requirements for entry? Delta Airlines has one that is very good, but when you input your personal data the options are fully vaccinated or not. There is no option for the definition of fully vaccinated.
I would hate to spend thousands of dollars booking flights and a tour or cruise and between the booking and the travel find that I don't meet the fully vaccinated requirement. This is especially true if the definition in the country of travel changes within 15 days of the trip, since you must get your shot prior to 15 days of travel.
Also, I am not keen on having to constantly get booster shots just to travel. Getting a booster shot every six months not going to happen.