That explains everything if true.
1. It explains why they seemed to all be on the same flight, because they all got off the same shuttle to the hotel, but only Earl has to quarantine.
2. It explain why Emily didn't really want to talk about it. What's she going to say, "Earl is the only idiot to not get vaxxed!" Even though I'm sure that's exactly what she's thinking.
3. It explains why Early referred to vaccination not providing complete protection in his post explaining why he had to quarantine. It seemed kind of irrelevant, but this would explain it.