Formula 1's Medical Car driver, Alan van der Merwe, is set to miss at least two of the remaining events on this year's calendar because he has not had the vaccination against COVID-19.
Van der Merwe, along with F1 doctor Ian Roberts, tested positive for coronavirus prior to the Turkish Grand Prix. He was replaced by Formula E's Safety Car driver Bruno Correia and will miss F1's two newest rounds at the end of the year.
Some countries require a vaccination status and, of the final six races, Qatar and Saudi Arabia currently demand proof of vaccination to enter the country, whilst paddock access in Abu Dhabi will also need evidence of a vaccine.
"From what we understand, there's a couple of countries that you probably won't be allowed to enter the country, unless you're vaccinated, which is no different to, let's call it in some parts of the world, malaria shots or whatever it might be, that you can't enter the country," F1 race director Michael Masi told RacingNews365.com and other select members of the press.
"You need to comply with those requirements to enter the country and from that perspective, the FIA obviously has to respect the country's requirements to get in, and as will all the teams and everyone else."
Van der Merwe revealed on social media that he will "avoid the very small but non-zero risks of a vaccine for now, until the data suggests it'll be advantageous" to him.
"In Switzerland (I'm half Swiss) and other developed countries, prior infection counts as much as a vaccine," added Van der Merwe.
"I trust that those countries know what they're doing, and also respect countries' more restrictive rules and not travel there.
"I am fully aware that I will potentially be less employable or that my freedom of movement will be restricted based on my choices.
"That I will not choose convenience over my own health does not mean I am making decisions out of selfishness. We all just want to be healthy."
Masi confirmed that Van der Merwe and Roberts tested positive for coronavirus independently and were "relatively OK" and available on the phone to assist the medical team at the weekend.
"Generally, we're very fortunate that within all of the various FIA championships, all us Race Directors talk very regularly.
"You've seen Eduardo Freitas who obviously is the WEC race director as clerk of the course in Portimao, and Scott Elkins and Niels Wittich, who are the Formula E Race Director and Deputy [Race Director] doing a number of events as my deputy," added Masi.
"So all of us working together is actually a regular thing and it's the same with the doctors. Bruno Correia has actually been one of our driver advisors in F2 and F3 this year.
"So effectively, it's the broad family, and it was great for both of them to be available at short notice, and they're always sort of our first reserves in the case of something like that happening, which none of us ever wish."
F1 Podcast: Do Mercedes need to assert more authority over Hamilton?
It's time for the latest episode of the RacingNews365 podcast, with F1 journalists Dieter Rencken, Thomas Maher and Mike Seymour discussing Lewis Hamilton's strategy drama and much, much more from the Turkish Grand Prix.