You’re unlikely to have a choice as to which COVID-19 vaccine you get, whether it’s Pfizer, Johnson & Johnson, or Moderna—but could the type of vaccine you get limit your travel options in the future?

First, it’s crucial to note that the important thing is that you get vaccinated against COVID-19 as soon as you can. As Dr. Fauci, director of the National Institute of Allergy and Infectious Diseases said, “All three of them are really quite good, and people should take the one that’s most available today.”

However, recent news out of China has some people worried over future vaccine travel regulations. More than 20 Chinese embassies around the world, including in the U.S., have recently issued new rules that restrict entry visas to China only to people who have received a China-made COVID-19 vaccine. 

The Chinese-made vaccines are not currently available in the U.S., and are not one of the four COVID-19 vaccines that have been approved by the World Health Organization (WHO). 

Likewise, the European Union (E.U.) recently announced plans for an Digital Green Certificate intended to open up safe and free movement to vaccinated citizens within the E.U. This digital certificate will be given to people who have recovered from COVID-19, received a negative test result, or have been vaccinated—with the caveat that only vaccines that have received E.U. marketing authorization will be counted for free movement, which does not include any of the Chinese-made vaccines. 

Experts are concerned that these rules could lead to “geopolitical vaccine silos”, in which certain parts of the world are only open to people that have had specific vaccines.

If this trend continues, it could cause people to try to get multiple vaccines in order to be able to travel to different destinations, which would strain the vaccine supplies even further. It could also put pressure on health organizations to prematurely approve different types of vaccines, in order to give citizens access to other countries.