Vaccine certificate incompatibility

December 07, 2021

One of the next big issues in post-pandemic travel and movement will be non-recognition and incompatibility of COVID-19 vaccination documentation between states.

Many states are starting to make vaccination against COVID-19 either a requirement of entry or a requirement in order to avoid expensive and prolonged post-travel quarantine. On its face, this is a reasonable thing to do, since it mitigates against the possibility that silent carriers of the SARS-CoV-2 virus enter the country and shed the virus, potentially seeding new outbreaks.

However, as a traveller, just because you got vaccinated, you’re not out of the woods!

For many, the assessment of whether one is considered “vaccinated” in a different jurisdiction is going to depend on much more than on just being vaccinated in-fact.

There are two areas in which this plays out. The first is at international boundaries, where the situation is a little better due to the need to deal with this every day, but significant pain points and inequalities still exist. The next is within states where the situation for vaccinations made outside the state is significantly more dire.

International Boundaries

At international boundaries, assuming that one has been vaccinated there are two issues that as a traveller, you are likely to need to contend with:

  1. Is your vaccine even “recognized” by the destination state?
  2. Is your vaccine documentation “valid” according to the destination state?


Regarding the first question, it appears as though the following vaccine products enjoy the most travel privileges, either because they’ve received local use approval, or emergency use authorization by the WHO:

  1. Comirnaty (aka Pfizer-BionTech)
  2. Spikevax (aka Moderna)
  3. Vaxzevria (aka AstraZeneca)
  4. Janssen (aka Johson & Johson)
  5. Sinopharm Beijing
  6. Covishield
  7. Covaxin
  8. CoronaVac

Those immunized with the following vaccine products are likely to face more problems at present, particularly in many of the “western” countries:

  1. Sputnik-V
  2. Sinopharm (unspecified or WIBP)
  3. Sinovac
  4. Zifivax
  5. Abdala (Cuba)
  6. EpiVacCorona (Russia, Belarus)
  7. Novavax (Indonesia)
  8. COVIran Barekat

Of particular note is Sputnik-V, which is in use in Russia and 75 other states. This product has no recognition within much of the EU, North Americas, China, parts of Africa and Australia. Within the EU, the rolling review process was started in March and as of December, is still stuck in the EMA’s bureaucratic process due to missing information. Its unclear to me why recognition of the vaccine for travel and border control purposes is tightly coupled with authorization for marketing and use within a juridiction. There might be problems with the data and other paperwork, but it seems as though Sputnik-V is at least effective enough for the purposes of deciding whether or not a particular traveller is safe to admit. Denying a person entry or treating them as though they are unvaccinated in this case also seems like a particularly strange personal responsibility to attach, given that for many people, if they were offered a vaccine at all, they didn’t exactly have a choice as to which vaccine to take.

For those who can afford it, this has now predictably resulted in the hassle of ”vaccine tourism”, where those who got the “wrong” vaccine are now travelling to states which don’t require the “right” vaccine on entry so that they can pay a lot of money in order to then get the “right” vaccine so that they can travel to their intended destination (for example, Russia to Serbia, for onward travel into the EU or USA).


However, just because you got the “right” vaccine, you’re still not out of the woods.

The next question is how to prove that you’ve been vaccinated to officials at the border. Here again, is a cocophony of different potentially incompatible solutions. Within the EU, things are not so bad due to the existence of the EU Digital Coronavirus Certificate scheme. However that only really solved the problem of mutual recognition within the EU and between a few states within the region.

Outside this system, there are no universally adopted standards, even if the vaccine products are identical. This leads to contradictory outcomes as to who is “vaccinated” based purely on technical compatibility. Within some states, this isn’t too bad - in the USA any document that looks like it came from an official source, specifies the name of the product, specifies the date of the final dose and is tied to some sort of personal identifier is acceptable. In the UK there is a fairly long list countries and acceptable corresponding documentation.

At Schengen borders, its a mess. For example, Norway accepts only the EU certificate, an equivalent certificate which implements the same technical specifications as the EU one (for which there is a small list of countries) or the NHS or Northern Ireland certificate. Everyone else is “unvaccinated” even if they are in fact vaccinated with an approved product. This has led to, for example, Australia, issuing a travel advisory clarifying that their “international certificate of vaccination” is not recognized as valid in Norway, and therefore anybody vaccinated in Australia and presenting an Australian certificate is treated as “unvaccinated”, even though it could be confirmed with roughly 30 seconds of internet searches both Norway and Australia use the same vaccine products. The reason for this isn’t that there is anything wrong with Australia’s vaccination programme or even the reliability of its certificates, but rather that Australia doesn’t use the same system for signing their certificates as is done in the the EU.

Particularly on the documentation front, what is maddening about this is that the airline industry body IATA already foresaw this issue and proposed a single universal standard that everyone could use. Which was then promptly ignored in favour of incompatible locally produced solutions.

Within states

However, again, just because a traveller has been fortunate enough to get the right vaccine and documentation accepted at the border, they are still not necessarily out of the woods!

Many states have now decided to implement “vaccine passports” which becomes a more regular part of everyday life. A vaccine passport can be required to dine at restaurants, enter shops, use public facilities or attend events with more than a fixed number of attendees.

But the definition of “what counts” as a vaccine passport varies quite wildly. Understandably, many states don’t want to leave it up to laypeople to interpret medical documentation, so have instead gone for a solution where a vaccination certificate contains a QR code scannable via a smartphone app. The app tells the event operator whether the attendance of the holder is permitted or not permitted.

These apps are typical authored by government departments or contractors within each state and also quite understandably only work with certificates produced under whatever regional scheme that state operates in. In Finland for example, this has led to the outcome where a person from the United States or United Kingdom is permitted to enter the country because their certificate of vaccination was “reliable” and therefore they are vaccinated, but then is not permitted to use a restaurant, use many public facilities or attend gatherings of more than 20 people, because their certificate of vaccination is not compatible with the scanning system and therefore they are “unvaccinated” (The restaurants association has since clarified to its own members that vaccination certificates from third countries are “fine”, though it is unclear what their legal basis for making that statement was, given that the relevant law quite clearly states that only the EU certificate may be used). The same issue also exists in New South Wales in Australia, where only the NSW certificate is usable.

Some areas recognize this problem and offer a mechanism to convert foreign certificates to local ones (with varying levels of stringency on the requirements of the original certificate to do so), other states don’t offer any solution at all, or only offer it to nationals or residents.

If one is unable to convert their foreign documentation to local documentation, then they are “unvaccinated” and can only fix that problem by getting vaccinated again, assuming that they’re eligible to be vaccinated in that location (which isn’t always the case). Or they’ll need use an “unofficial workaround”.

For example, those who want an EUDCC certificate for use in a state in the EU can apparently book a refundable travel package to Switzerland, then upload their certificates and flight booking to the provided service in order to get a certificate that is then valid in the EU. So in order to be “vaccinated” in state A, you need to upload to state B your proof of vaccination from state C so that you can get a certificate from state B that happens to be valid in state A, even though state A won’t accept a proof from state C. Makes perfect sense.

As a software engineer, all of this technical incompatibility is maddening in the sense that it could have easily been both foreseen and solved by implementing international standards that were already proposed. But alas, everyone wanted to have their own solution, so now we live in a world where that has happened.

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Written by Sam Spilsbury an Australian PhD student living in Helsinki.