>>12921331High IQ people critically think about their opinions and what they believe, which can lead them to adopt non-mainstream beliefs provided there's enough evidence against the mainstream.
On the other hand, irrational nonconformism is both peak low IQ and midwit. The former do it because of low agreeablness personality and antisociality, both of which correlate with low IQ. The latter do it because they want to feel special and different from the "sheep". Either way both don't critically think and whether they are right or wrong depends entirely on whether if the mainstream opinion is correct or not.
In this thread's case, anyone who looks at the evidence knows that most Covid vaccines work, and that covering your nose and mouth with anything reduces the chance of infection.