Not exactly a scientific view he is espousing here. There could be dozens of risk factors that this person has, and Elron would not know about them. He is just such a moron, too - what he said is his usual pretentious mishmash and it means absolutely nothing.
"Could be the vaccine, but maybe not, we don't know if the vaccine does this a lot, or not". Wow, thanks, smartest guy on the planet.
He's even dumber than that. He's not just saying "could be the vaccine, could be not"; he's literally saying "you can't say it's the vaccine and you can't say it's not."